Three numbers P, Q, and R are in the ratio 1:2:3, and their average is 600. If P is increased by 10% and Q is decreased by 20%, then by how much should R be increased to raise the overall average by 5%?

An institution has 5 classes containing 50, 60, 25, 40, and 70 students. The pass percentages of these 5 classes are 20%, 25%, 20%, 10%, and 30% respectively. Find the average number of passed students per class in the institution.

If the Consumer Price Index (CPI) increases from 125 in 1995 to 140 in 1996, what is the annual rate of inflation?