Question

Ben solved a fraction division problem using the rule “multiply by the reciprocal.” Look at his work.

StartFraction 7 Over 20 EndFraction divided by two-fifths. StartFraction 20 Over 7 EndFraction times two-fifths = StartFraction 40 Over 35 EndFraction = StartFraction 8 Over 7 EndFraction = 1 and StartFraction 1 Over 7 EndFraction

Did he solve the problem correctly?
Yes. He solved the problem correctly.
No. He multiplied the dividend by the divisor.
No. He multiplied the denominators instead of finding a common denominator.
No. He multiplied with the reciprocal of the dividend instead of with the reciprocal of the divisor.

Answer 1

D) No. He multiplied with the reciprocal of the dividend instead of with the reciprocal of the divisor.

Explanation:

Answer 2

(d) No. He multiplied with the reciprocal of the dividend instead of with the reciprocal of the divisor.

Explanation:

The problem should have been written ...

`(7)/(20)/(2)/(5)=(7)/(20)*(5)/(2)\qquad\text{the reciprocal of the divisor is used}`

Instead, Ben wrote it as ...

`=(20)/(7)*(2)/(5)\qquad\text{the reciprocal of the dividend is erroneously used}`

_____

Additional comment

Ben will get the reciprocal of the proper answer: 8/7 instead of the correct value of 7/8.