Question

Molly can prepare a report in 6 hours. Jere can prepare a report in only 4 hours.

Which of the following can be used to determine the amount of time it would take for Molly and Jere to prepare a report together?

Answer 1

Total time taken by Molly and Jere to prepare a report together = 2.4 hours

Explanation:

Time taken by Molly to prepare a report = 6 hours

`\text{So, one hour work of Molly = }(1)/(6)\text{ hours}`

Time taken by Jere to prepare a report = 4 hours

`\text{So, one hour work of Jere = }(1)/(4)\text{ hours}`

Now, we need to calculate the total time taken by Molly and Jere to prepare a report together.

`\text{Time taken by Molly and Jere to prepare a report together = }(1)/(6)+(1)/(4)\\\\\implies (6+4)/(24)\\\\\implies (10)/(24)\\\\\implies \text {Total time taken by Molly and Jere to prepare a report together = }(24)/(10) =2.4\text{ hours}`

Hence, Total time taken by Molly and Jere to prepare a report together = 2.4 hours

Answer 2

Answer with explanation:

Time taken by Molly to prepare the Report = 6 hours

Work done in 1 hour
`=(1)/(6)`

Time taken by Jere to prepare the Report = 4 hours

Work done in 1 hour
`=(1)/(4)`

Their Combined Work , is given by the equation

`=(1)/(6)+(1)/(4)\\\\=(6+4)/(6* 4)\\\\=(10)/(24)`

Time it would take for Molly and Jere to prepare a report together is equal to

`=(24)/(10)\\\\=2.4`

= 2.4 hours