Which of the following is not equal to 6.7meters

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

Consider circle c with angle acb measuring 3/4 radians.if minor arc ab measures 9 inches, what is the length of the radius of circle c? if necessary, round your answer to the nearest inch.

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour.what is the cyclist average rate for the round trip in miles per hour ?