you know that there are 1609 meter in a mile. the number of feet in a mile is 5280. what is the speed snail from problem 7 per minute.

We know that 1 meter = 100 centimeters, and 1 foot = 12 inches.

So  (1,609 meters) x (100 centimeters/meter)  =  (5,280 feet) x (12 inches/foot)

The second fraction on each side of the equation is equal to ' 1 ', because

the numerator is equal to the denominator, so sticking it in there doesn't

change the value of that side of the equation.  But now we can cancel some

units,and wind up with the units we need.

  (1,609 meters) x (100 centimeters/meter)  =  (5,280 feet) x (12 inches/foot)

        (1,609 x100) centimeters  =  (5,280 x 12) inches

            160,900 centimeters  =  63,360 inches

Divide each side by  63,360 :        2.54 centimeters =  1 inch

Explanation:

the part of the wave he is travelling on is the crest