What is the sales tax for a purchase of $2,500 ?

Prove that the sum of two consecutive exponents of the number 5 is divisible by 30.if two consecutive exponents are 5n and 5n + 1, then their sum can be written as 30.

The hawaiian alphabet has 12 letters. how many permutations are posible for each number of letters?

At oaknoll school, 90 out of 270 students on computers. what percent of students at oak knoll school do not own computers? round the nearest tenth of a percent.