How many pairs of twin primes are there between the integers 1 to 100? 

A number which when divided by 10 leaves a remainder of 9 , when divided by 9 leaves a remainder of 8 , and when divided by 8 leaves a remainder of 7 , is :

Simplified form of $$ [(^5\sqrt{x^{-3\over 5}}\ )^{-5\over3}]^{-5}$$

A man invested a sum of money in Scheme A, at a rate of 15% per annum for simple interest, at the end of 2 years the amount received by him is invested in scheme B at 20% per annum for compound interest. If the interest received by him from scheme B at the end of 2 years is Rs. 2860, then find the sum invested by man in the beginning?

Twice the square of a number is three times the cube of other number. What is the ratio between the first number and the second number? 

If 32 is removed from the data: 20, 25, 28, 32, 38, 45, 48, 52, then the median s increaser by?

A dealer sells an article for ₹ 24 and gains as much percent as the price of the article , then the cost price of the article is: 

Let x be the least number which when divided by 8, 12, 20, 28, 35 leaves a remainder 5 in each case. What is the sum of digits of x?