Question

A washing machine is filling up with water at a constant rate. The rate is 3/4 of a gallon in 1/5 of a minute. Don calculated the unit rate to be 3/20 of a gallon per minute. what did he do wrong?​

Answer 1

Answer: you have to see how many gallons fill the container per minute, so take 3/4 and divide it by 1/5, which gives 15/4. So he multiplied the two numbers instead of dividing.

Explanation:

Answer 2

`(15)/(4)` gallon per minute

Explanation:

Given parameters:

Quantity of gallon =
`(3)/(4)` gallon

Time taken =
`(1)/(5)` min

Unknown:

The solution is
`(3)/(20)` gallon per minute, what did he do wrong = ?

Solution:

To find the rate:

Rate =
`(Quantity of gallon)/(time )`

Input the parameters and solve

Rate =
`((3)/(4) )/((1)/(5) )` =
`(3)/(4)` ÷
`(1)/(5)`

Invert the
`(1)/(5)` to give 5

=
`(3)/(4)` x 5

=
`(15)/(4)` gallon per minute

The student failed to invert the
`(1)/(5)` before multiplying with
`(3)/(4)`