Question

Karen is training for her upcoming track meet. She makes 3 practice runs in a 1.5 hour time period. She runs 3/4 the distance of each of previous run. If she ran 5 miles on the first run, how far will she go on her third run?

Answer 1

She will go 2.8125 miles in her third run

Explanation:

- Karen is training for her upcoming track meet

- She makes 3 practice runs in a 1.5 hour time period

- She runs
`(3)/(4)` the distance of each of previous run

- If she ran 5 miles on the first run, how far will she go on her third run

- Assume that she will run x miles in her 1st run

∵ The distance of the 1st run is x

∵ She runs
`(3)/(4)` the distance of each of previous run

∴ The distance of her 2nd run is
`(3)/(4)x`

∴ The distance of her 3rd run is
`(3)/(4)` (
`(3)/(4)x`)

∴ The distance of her 3rd run is
`(9)/(16)x`

∵ She ran 5 miles on the 1st run

- Substitute x by 5

∴ The distance of her 2rd run =
`(3)/(4)(5)`

∴ The distance of her 2rd run = 3.75 miles

∴ The distance of her 3rd run =
`(9)/(16)(5)`

∴ The distance of her 3rd run = 2.8125 miles

* She will go 2.8125 miles in her third run