If mean of P, Q, R, S, T is 100 and mean of Q, R, S, T, U is 120 and P + U = 100, what is the mean of P, Q, R, S, T and U?

The mean of p, q, r, s and t is 280. If the mean of p, r and t is 240, what is the mean of q and s?

If M is the mean of the first 100 even natural numbers, then what is the mean of the first 100 odd natural numbers?

The average of 308, 125, 45, 120 and 102 is:

If the mean of a set of observations x₁, x₂, x₃, ..., x₁₀ is 20, then the mean of x₁+5, x₂+10, x₃+15, ..., x₁₀+50 is:

If the average of m numbers is n*n and that of n numbers is m*m , then the average of m+n numbers is