Mathematics Puzzle test (2-4-2015) PowerPoint

Puzzle ppt

1. Puzzle test

2. How many times can you take 3 from 25?

3. Ans- only one time , 25 – 3 = 22

4. What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

5. Ans - 5.9

6. You have to distribute 3 apples in two mother and two daughter and each should have one apple.

7. Grand Mother Mother Daughter Answer :

8. There is an old bridge over river Ganga . Four peoples wants to cross the bridge at night. Many places are missing and the bridge can hold only two peoples at a time. The travelers must use a torch to guide their steps; otherwise they are sure to step through a missing space and fall to their death. There is only one torch . The four peoples each travels at different speeds. A can cross the bridge in one minute ; B in two minutes ; C takes five minutes and the slowest person, D takes ten minutes . The bridge is going to collapse in exactly 17 minutes . How can all four peoples cross the bridge?

9. A lady and a mathematician are traveling in an airplane. The lady challenges the mathematician to solve her question. Here’s the sequence of events that follow. Lady : “guess my 3 daughter’s ages” Mathematician : “Alright…give me some clues” Lady : “Clue 1: The product of their ages is 36” Mathematician : “I can’t find their ages. I need one more clue” Lady : “Clue 2: Sum of their ages is your seat number” Mathematician : “I still can’t find out” Lady : “Clue 3 : My youngest daughter has blue eyes” Mathematician : “ I got their ages” What is the seat no. ? What are the ages ? Thought Flow Case 1 : Lady and the Mathematician

10. PRODUCT 1 x 1 x 36 1 x 2 x 18 1 x 3 x 12 1 x 4 x 9 1 x 6 x 6 2 x 2 x 9 2 x 3 x 6 3 x 3 x 4 SUM 38 21 16 14 13 13 11 10 ?? ->Youngest Seat No. 13… ages 1,6,6 Thought process After the first clue Thought process after the second clue Significance of The Third clue Case 1 : Solution

11. OK , Do this …. In the above figure, the six red lines are placed equidistant from each other on OA and their tops lie on the line joining A and B. What is the total length of all these 6 red lines? 17 cms. 13 cms. A o B

12. Benefits… 17 cms. 13 cms. A O B C 6 lines x 13 cms. = 78 cms. = total length of red+green lines. Total length of red lines alone = 78 / 2 = 39 cms .

13. A vagabond runs out of cigarettes. He searches for the stubs, having learnt that 7 stubs can make a new cigarette , good enough to be smoked, he gathers 49 stubs, If he smokes 1 cigarette every three - quarters of an hour , how long will his supply last ? (A) 5.25 hr (B) 6 hr (C) 4.5 hr (D) 3 hr

14. Ans – 49 stubs = 7 cigarettes The duration of time he will take to smoke these 7 cigarettes in hr = 5.25 hr (i.e. 5 hr and 15 min ). Now note that after he has smoked these 7 cigarettes , he will collect 7 more stubs (one form each), form which he will be able to make another cigarette. This will take him another hr (45 min) to smoke. Therefore, total time taken = 6hr.

15. Four-Digit Whole Number There is one four-digit whole number n, such that the last four digits of n 2 are in fact the original number n.

16. Ans- Looking at the last digit, the last digit must be either 0, 1, 5 or 6. Then looking at the last two digits, the last two digits must be either 00, 01, 25 or 76. Then looking at the last three digits, the last three digits must be either 000, 001, 625 or 376. Then looking at the last four digits, the last four digits must be either 0000, 0001, 0625 or 9376. Out of those, only 9376 is a 4 digit number.

17. A man has 3 sons and a property of 17 cows. On his death bed, he says to his attorney, that let my eldest son have one half of my property, next son have one third and the youngest one have one ninth. What should the attorney do?

18. Birthday When asked about his birthday, a man said: "The day before yesterday I was only 25 and next year I will turn 28." This is true only one day in a year, when was he born?

19. Ans - He was born on December 31st and spoke about it on January 1st.

20. A set of three light switches are located in the first floor of a building. Only one of them turns on a light on the second floor . The other two switches do nothing. If you can only go up the stairs one time, and you can't see the second floor light from the first floor, how can you be sure which switch turns on the second floor light?

21. Prashant wants to distribute 127 one rupee coins in to different piggy banks so that any integer sum from 1 through 127 rupees cab be paid by just handing over the piggy banks without having to break open the piggy banks. What is the minimum number of piggy banks required?

22. Ans – 1 2 4 8 16 32 64

23. One of your employees insists on being paid daily in silver. You have a silver bar whose value is that of seven days salary for this employee. The bar is already segmented in to seven equal pieces. If you are allowed to make just two cuts in the bar , and must settle with the employee at the end of each day, how do you do it?

24. Sudeep has 11 packs of cigarettes and in each pack there are 10 cigarettes. One of the packs is defective in the sense that each cigarette in that pack weighs one gram less than the ones in the rest of the packs. The weight of a single non-defective cigarette is 2.5 grams . He wants to identify the defective cigarette packet. In how many weighing can he definitely identify it if we has I : A weighing balance, which can only compare weights. II : A weighing machine, which can read the exact weights. a. I : 1 and II : 3 b. I : 3 and II : 3 c. I : 3 and II : 5 d. I : 3 and II : 1

25. Ans – d. I : 3 and II : 1

26. You have two candles. Each will burn for exactly one hour. But the candles are not identical and do not burn at a constant rate. There are fast-burning sections and slow-burning sections. How do you measure forty-five minutes using only the candles and a lighter ?

27. You have 12 similar looking coins . 11 of them weigh the same . One of them has a different weight , but you don’t know whether it is heavier or lighter. You also have a scale. You can put coins on both sides of the scale and it’ll tell you which side is heavier or will stay in the middle if both sides weigh the same. What is the minimum number of weighing required to find the odd coin .

28. In a distant dark forest, 400 highly intelligent dwarfs live, all look exactly alike , but the only difference is that they are wearing either a red or a black hat . The dwarf does not know the color of his hat . The only thing they know is that there is at least one red hat and one black hat . Unfortunately they can not communicate among themselves. Now, there is a big party in the forest which lasts for 1 year , to which initially all dwarfs go. However, this party is intended for dwarfs wearing black hats only . Dwarfs with red hats are never supposed to return to the party again as soon as they realize that they are wearing red hats. All 400 dwarfs keep on coming to the party for 200 days. Exactly on 201 st day , not a single dwarf wearing red hat appeared. How many dwarfs were there in the group wearing red hats?

29. Kumbhakarna starts sleeping between 1 pm and 2 pm and he wakes up when his watch shows such a time that the two hands (hour hand and minute hand) interchange the respective places. He wakes up between 2 pm and 3 pm on the same night. How long does he sleep?

30. A bag contains coins of four different denomination, 1 rupee, 50 paise , 25 paise and 10 paise . There are as many 50 paise coins as the value of 25 paise coin in rupees. The value of 1 rupee coins is 5 times the value of 50 paise coins. The ratio of the number of 10 paise coins to that of 1 rupee coins is 4 : 3 , while the total number of coins in the bag is 325. Q. How many 10 paise coins are there? Q. What is the total value of coins in the bag?

31. A vending machine has five switches which when operated give coca-cola, 7-up, mirinda, limca , and pepsi depending upon the switches that are turned on. The machine is such that each switch supplies two different drinks and each drink is supplied by two different switches . If two switches are turned on , the common drinks if any, nullify each other and will not come out at all. 1 and 3 gives 7-up and mirinda. 1 and 2 gives coca-cola and pepsi. 1 and 4 gives limca, coca-cola, mirinda and pepsi. Switches 1,2,3,4 and 5 do not supply 7-up, limca, coca-cola, mirinda and pepsi respectively. Q. Which drins are supplied by turining on switches 2 and 3 ? Q. Coca-cola is one of the drinks which will be supplied by turning on switches. (a) 1 and 3 (b) 1 and 5 (c) 2 and 4 (d) 2 and 5

32. There are one thousand lockers and one thousand students in a school. The principal ask the first student to go to each lockers and open it. Then he ask the second student go to every second locker and close it. The third student goes to every third locker, and if it is closed, he opens it, and if it is open, he closes it. The fourth student does it to every fourth locker and so on. The process is completed with all the thousand students. Q. How many lockers are closed at the end of the process? Q. How many students can go to only one locker?

33. Ans – There are 31 perfect squares between 1 to 1000. perfect squares have odd no. of factors so the lockers having these no. are open. no. of closed lockers = 1000- 31= 969 500 students go to only one locker.

34. DATA SUFFICIENCY

35. Is the perimeter of triangle ABC greater than 20? 1. BC-AC = 10 2. the area of the triangle is 20.

36. Ans – both 1 and 2 alone are sufficient.

37. If vertices of a triangle have coordinates (-1,0), (4,0), (0,A), is the area of triangle greater than 15. 1. A < 3 2. the triangle is right.

38. Ans – only 2 is sufficient

39. Are x and y both positive? 1. 2x – 2y = 1 2. x/y > 1

40. Ans – both 1 and 2 are required.

41. Ten years ago, scientists predicted that the animal z would become extinct in ‘t’ years. what is t. 1. animal z became extinct 4 years ago. 2. if the scientists had extended their extinction prediction for animal z by 3 years , their prediction would have been incorrect by 2 years.

42. Ans - both 1 and 2 together are not sufficient.

43. The total cost of producing item x is equal to the sum of item x’s fixed cost and variable cost. If the variable cost of producing x decreased by 5% in january , by what percent did the total cost of producing item x change in january . 1. the fixed cost of producing item x increased by 13% in january . 2. before the changes in january , the fixed cost of producing item x was 5 times the variable cost of producing item x.

44. Ans – both 1 and 2 together are sufficient.

45. If x and y are non zero integers and |x| + |y| = 32, what is xy? 1. -4x – 12y = 0 2. |x| – |y| = 16

46. Ans – only 1 is sufficient.

47. If k is an integer greater than 1, is k equal to 2^r for some positive integer r ? 1. is divisible by 2^6 2. k is not divisible by any odd integer greater than 1

48. Ans – only 2 is sufficient.