What is the mean of the following numbers: 9, 15,

[16 × 15 + 224 × 5] ÷ 5 = ? × 4

The sum to n terms of the series 1 + 1 + 3 + 1 + 3 + 5 + 1 + 3 + 5 + 7 …………………… is

The 5th and 8th term of an arithmetic progression are 13 and -5 respectively. What is the 15th term?

Sum of first 20 terms of an AP is 610. First term = 12. Find approximate common difference.

21 is divided into three parts which are in arithmetic progression (A.P.) in such a way that the sum of their square is 179. Find the smallest part.

What is least number which when successively divided by 6, 4 and 4 leaves a remainder 5, 3 and 3 respectively?

The arithmetic mean and geometric mean of two numbers are 7 and 2√10 respectively, then find the numbers.

5 years ago, A was 1/3 of B’s age. If the ratio of their present ages is 2:5, what will be the sum of their present ages?

‘479385A267’ is ten-digit number which is divisible by 9, what is the value of ‘A’?