A whole number is doubled and 9 added. The result is tripled and becomes 171. If 3 is subtracted from the given number, result divisible by

The sum of the reciprocals of A’s ages (in years) 2 years ago and 2 years from now is 2/3. The present age of A is

If z = x + iy is a complex number such that iz = 2 + 3i, then the value of x − y is

The age of Q exceeds the age of P by 3 years. The age of R is twice the age of P and the age of Q is twice the age of S. Further, the age difference of R and S is 30 years. What is the sum of the age…

If a, b, c, d, e and f satisfy 2a = 3b = 6c = 9d = 12e = 18f, then what is the value of (a + b)/(c + d + e + f)?

Suppose n is an integer such that the sum of the digits of n is 2, and 10¹⁰ <n < 10¹¹, The number of different values for n is