Brain Teasers

Jai Ganesh · 2006-03-15 16:41:55

(17) There are two consecutive natural numbers whose product is equal to the product of three consecutive natural numbers. Can you find the numbers?

mathsyperson · 2006-03-16 04:01:39

17. (2,3) and (1,2,3)?

Jai Ganesh · 2006-03-16 04:24:53

Correct! Welldone! But I had (14,15) and (5,6,7) in my mind!

Jai Ganesh · 2006-03-17 04:29:42

(18) If the two digits of Mr.M are reversed, then the new age obtained is the age of his wife. 1/11 of the sum of their ages is equal to the difference between their ages. Mr. M is older than his wife. What's the difference between their ages?

Jai Ganesh · 2006-03-17 19:17:58

(19) A 5 digit number when multiplied by 4 gets reversed. What is the number?

Jai Ganesh · 2006-03-17 19:20:48

(20) John is 10 times faster on his bike than oh his bicycle. One day he goes to the market on his cycle for some time and then by his bike. He takes 1/4th of the time he usually takes on his bicycle to the market. What fraction of the distance did he ride the bicycle?

Jai Ganesh · 2006-03-17 20:16:32

(21) In a group of six women, there are four table-tennis players, four post-graduates in Economics, one post-graduate in Commerce and three Bank employees. Venus and Kate are among the bank employees while Alice and Maggie are unemployed. Maggie and Nancy are among the table-tennis players. Alice, Kate, Maggie and Nancy are post graduates in Economics of whom two are bank employees. If Sally is a post graduate in Commerce, who among them is both a teble tennis player and a bank employee?

Jenilia · 2006-03-19 01:08:46

I seriously have no idea, but I think the answer is {this}

Jai Ganesh · 2006-03-19 02:45:16

22. Adam travels halfof his target distance on his bike at 20kilometres per hour. At what speed should he travel the remaining half distance in order to have average speed of the total travel as 60 kilometres per hour?

23. A cable that is 18 metres in length hangs between two pillats, both of height 28 metres. The ends of the cable are attached to the tops of the pillars. At its lowest point, the cable hangs 19 metres above the ground. How far apart are the two pillars?

Jai Ganesh · 2006-03-20 15:59:43

24. Find the largest ten digit number made up of all numbers 0,1,2,3,4,5,6,7,8, and 9, and divisible by 11.

Jai Ganesh · 2006-03-21 18:30:47

24. Fill in the balnk to make the sentence true.

This sentence has _______________________ letters.

(Fill it in three different ways).

mathsyperson · 2006-03-22 04:17:32

Jai Ganesh · 2006-03-22 04:37:21

Well done, mathsyperson! The third possibility I had thought of was

Jai Ganesh · 2006-03-22 15:11:54

25. A chocolate costs 50 cents, a pen costs $3 and a notebook costs $10. How would you buy 100 items for $100?

rm · 2006-03-22 22:52:08

Jai Ganesh · 2006-03-22 22:54:51

Well done, rm!

rm · 2006-03-23 00:06:34

Jai Ganesh · 2006-03-23 03:33:47

Excellent, rm! Keep it up!

Jai Ganesh · 2006-03-23 15:30:43

26. A person travelled from one place to another at an average speed of 40 kilometres/hour and back to the original place at an average speed of 50 kilometres/hour. What is the average speed of the entire round-trip?

27. A student has 60% chance of passing in English and 54% of passing in both English and Mathematics. What is the probability in percentage of his failing in Mathematics?

rm · 2006-03-24 03:47:32

Jai Ganesh · 2006-03-24 03:57:43

Very well done, rm!

Jai Ganesh · 2006-03-24 04:25:39

28. In a day (24 hours), how many times are the minute hand and hour hand of a clock at right angles?

Jai Ganesh · 2006-03-24 15:58:46

29. Out of all the fifty students in a nuresery, all the students speak English or Spanish or both. Some speak only English and some speak only Spanish. Ten students speak both English and Spanish. If 21 students speak English, how many speak Spanish, how many of them speak only Spanish and how many only English?

30. I purc hase two wristwatches A and B for $650. I sell A at a profit of 20% and B at a loss of 25% and sell both A and B at the same price. How much did watches A and B cost me?

31. In a family of four, the age of the father is three times that of his daughter and the age of the son is half of his mother. The wife is nine year younger than her husband and the son is seven years elder than the daughter. What is the age of the mother?

32. A, B, C, D, E, and F are sitting on six chairs placed around a round table, not necessarily in that order. A is between D and F. C is opposite D and D and E are not sitting next to each other. Which of these pairs are sitting next to each other?
(i) A and B (ii) C and E (iii) B and F (iv) A and C

Ninja 101 · 2006-03-31 02:52:50

ganesh wrote:

25. A chocolate costs 50 cents, a pen costs $3 and a notebook costs $10. How would you buy 100 items for $100?

i can't read it. cobalt colours.

Last edited by Ninja 101 (2006-03-31 02:53:43)

Jai Ganesh · 2006-03-31 18:39:23

Can you read it now?
25. A chocolate costs 50 cents, a pen costs $3 and a notebook costs $10. How would you buy 100 items for $100?

Math Is Fun Forum

#26 2006-03-15 16:41:55

Re: Brain Teasers

#27 2006-03-16 04:01:39

Re: Brain Teasers

#28 2006-03-16 04:24:53

Re: Brain Teasers

#29 2006-03-17 04:29:42

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#30 2006-03-17 19:17:58

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#31 2006-03-17 19:20:48

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#32 2006-03-17 20:16:32

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#33 2006-03-19 01:08:46

Re: Brain Teasers

#34 2006-03-19 02:45:16

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#35 2006-03-20 15:59:43

Re: Brain Teasers

#36 2006-03-21 18:30:47

Re: Brain Teasers

#37 2006-03-22 04:17:32

Re: Brain Teasers

#38 2006-03-22 04:37:21

Re: Brain Teasers

#39 2006-03-22 15:11:54

Re: Brain Teasers

#40 2006-03-22 22:52:08

Re: Brain Teasers

#41 2006-03-22 22:54:51

Re: Brain Teasers

#42 2006-03-23 00:06:34

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#43 2006-03-23 03:33:47

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#44 2006-03-23 15:30:43

Re: Brain Teasers

#45 2006-03-24 03:47:32

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#46 2006-03-24 03:57:43

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#47 2006-03-24 04:25:39

Re: Brain Teasers

#48 2006-03-24 15:58:46

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#49 2006-03-31 02:52:50

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#50 2006-03-31 18:39:23

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