Chris and lisa went shopping and spent a total of $25.50. lisa spent $13.50 more than what chris spent. how much did lisa spend?

The circumference of a redwood tree trunk is 20π ft, and it is 100 ft tall. what is the approximate volume of the redwood tree trunk? 1,000π ft3 10,000π ft3 4,000π ft3 40,000π ft3

If y varies directly as x2 and y=6 when x=6, find the constant of variation.

If value of cos330° is √3/2 then find tan165°.