The cost price of 20 articles is the same as selling price of 15 articles. The profit percentage in the transaction is

Present age of Krishna is 1 /4th that of her father’s present age. After 4 years the sum of their ages will be 68. What is the
present age of Krishna?

The sum of the digits of a two digit number is 10. If the places of the digits are exchanged, the new number is greater than
the original number by 18, what is the original number?

A started from a point and went 4 kms north and turned left and moved 2 kms. west. Then he turned left and moved 4 kms.
How far is he away from his starting point?

Which of the following is a rational one?

The number of primes between 59 and 101 is –––.