The number 142<sup>2</sup> - 1 is divisible by :

What will be the unit digit in the 7<sup>105</sup> ?

7<sup>6n</sup>- 6<sup>6n</sup>, where n is an integer >0, is divisible by

Which one of the following is not a prime number?

Let N = 1421 × 1423 × 1425. What is the remainder when N is divided by 12?

Find the remainder when 65<sup>203</sup> is divided by 7.

A man read $$\frac{2}{5}$$ th of a book on the first day. He read $$\frac{1}{3}$$ rd more on second day than he read in …

A virus known to cause a deadly disease, is also a rapid multiplier. It is known that it can double itself every 30 minu…