If 53 = 10 and 78 = 49, then 67 is equal to

If 10 → 4, 18 → 6 and 30 → 8, then 48 → ?

If p is the difference between a number and its reciprocal and q is the difference between the square of the same number and the square of its reciprocal, then what is p⁴ + 4p² equal to ?

Find the remainder when 49^49 + 1 is divided by 6.

The sum of two numbers is 480. If the bigger number is decreased by 2% and the smaller number is increased by 10%, then the numbers obtained are equal. The larger number is approximately

In an enclosure there are crows and cows. If there are 30 heads and 100 legs, what is the ratio of cows to crows?