There are red checkers and black checkers,20 checkers in all. there are 8 more red checkers than black checkers. how many red checker and how many black checkers

(! ) three cylinders have a height of 8 cm. cylinder 1 has a radius of 1 cm. cylinder 2 has a radius of 2 cm. cylinder 3 has a radius of 3 cm. find the volume of each cylinder

Ageologist had two rocks on a scale that weighed 4.6 kilograms together.rock a was 0.5 of the total weight.how much did rock a weigh?

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'