The average of six consecutive odd numbers is 26. Find the difference between the largest and the smallest of these numbers.

Divide 50 into two parts so that the sum of their reciprocals is   $${1\over 12} $$

Find the average of the cubes of the first five natural numbers. 

For which value of x the seven-digit number 8439x53 is divisible by 99?

The second number in the given number-pairs is obtained by performing certain mathematical operation(s) on the first number. The same operation(s) are followed in all the number-pairs EXCEPT one. Find that odd number-pair.

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 :

Evaluate 743 x 999.

3¹¹ + 3¹² + 3¹³ + 3¹⁴ is divisible by which of the following?