Trigonometry 

The number of roots between 0 and π of the equation 2sin2x + 1 = 3sinx equals

(A) 2
(B) 4
(C) 1
(D) 3

Read More

Truth Day 


Philip lies a lot.

[1] He tells the truth on only one of the days of the week.

[2] The days of the week in order are:
Sunday, Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday,Monday,etc.

[3] One day he said: “I lie on Mondays and Tuesdays”.

[4] The next day he said: “Today is either Thursday, Saturday, or Sunday”.

[5] The next day he said: “I lie on Wednesdays and Fridays”.

On which day of the week does Philip tell the truth?

See our previous ‘Puzzles of the Day’:

Three Letter Word


Here is a list of words:

INN PEN PET PIE TEE TIE
[1] A wise man tells three knights, “I have told each of you a letter found in the three-letter word. I have told none of you the same letter.”
[2] He then tells them, “None of you can tell how many vowels the word has.”
[3] Then they are told, “At this point still none of you can tell how many vowels the word has.”
[4] Now knight no 3 says he knows what the word is.

What is the word?

Source: The Great Book of PUZZLES & TEASERS

Read More

Numbers 

Chandni had twice as many blueberry jelly beans as cherry jelly beans. After eating 10 pieces of each kind, she now has three times as many blueberry jelly beans as cherry jelly beans. How many blueberry jelly beans did she originally have?

1. 10
2. 20
3. 30
4. 40

See our previous ‘Questions of the Day’:

Numbers/Counting


The number 21! = 51090942171709440000 has over 60,000 positive integer divisors. One of them is chosen at random. What is the probability that it is odd ?

1. 1/21
2. 1/18
3. 1/19
4. 1/2

See our previous ‘Questions of the Day’: 

Collection of Coins 


A large bottle contains a collection of coins. When you examine the contents you are amazed to discover that there is an equal number of each type of denomination: 1 p, 2 p, 5 p, 10 p, 20 p, 50 p, Re 1, and Rs 2. Even more remarkable is that if you remove one coin there will be an exact amount in rupees. What is the smallest amount, in rupees, that could be in the bottle after removing that coin?

See our previous ‘Puzzles of the Day’:

Geometry  

A three-dimensional rectangular box with dimensions X, Y and Z has faces whose surface areas are 24, 24, 48, 48, 72, and 72 square units. What is X + Y + Z?


Read More

Recent Forum Posts/Questions/Answers