The average of P numbers is Q4, the average of Q numbers is P 4. The average of (P+Q) number is?

The average of P numbers is Q4, the average of Q numbers is P 4. The average of (P+Q) number is?

a) QP

b) PQ(P2 + Q2)

c) PQ(P2+Q2-PQ)

d) P2+Q2

Sol:

Sum of P number = PQ⁴

Sum of Q number = QP⁴

(P + Q) = PQ⁴ + QP⁴