Acomputer store has 75 printers of which 35 are laser printers and 40 are ink jet printers. if a group of 10 printers is chosen at random from the store, find the mean and variance of the number of ink jet printers.

Prism m and pyramid n have the same base area and the same height. cylinder p and prism q have the same height and the same base perimeter. cone z has the same base area as cylinder y, but its height is three times the height of cylinder y. the figures and have the same volume.