Darren bought 20 stamps. n of these were 20p stamps. The rest were 30p stamps. He spent £5.20 altogether.
How many 20p stamps did he buy?

Anumber cube is rolled two times in a row. find the probability it will land on 2 on the first roll and a number greater then 4 on the second roll

If t8 = 4 and t12 = −2, find the first three terms of the arithmetic sequence.

Charlie is at an amusement park that has 18 different rides. each ride costs $1.75. the function c(r) = 1.75r represents the total amount of money that charlie will spend if he goes on r rides, but he never goes on the same one more than once. what domain and range are reasonable for the function?