A's income is 40% more than B's income. How much per cent is B's income less than A's?

The average of four numbers A, B, C and D is 40. The average of four numbers A, B, E and F is also 40. (A, B are common). Which of the following must be true ?

A fan of Sachin Tendulkar doesn’t exactly remember his test average but remembers that it is an integer greater than 45 and less than 60. Another fan also doesn’t remember the exact average but remembers that it is an integer greater than 35 and less than 47. Which of the following is the actual average?

The average of three consecutive natural numbers is 61. What is the sum of the first and last numbers?

65% of a number is more than its two-fifth by 140. What is 30% of that number ?