Question

You are swimming each 25 yd length of a swimming pool 3 seconds faster than your personal best. What integer represents your change in time of your personal best after 200 yards?

Answer 1

Answer: +24.

Explanation:

Given : You are swimming each 25 yd length of a swimming pool 3 seconds faster than your personal best.

i.e. for each 25 yd length of a swimming round, +3 seconds faster than your personal best.

If the swimming timing is 200 yards, then the number of 25 yd length round of swimming in it :-

`n=(200)/(25)=8`

Then, the change in time of your personal best after 200 yards :-

`8*(3)=24\text{ seconds}`

Hence, the integer represents your change in time of your personal best after 200 yards = +24.

Answer 2

Suppose the number of laps = m

According to the question, each lap of 25 yards is covered 3 seconds faster than the previous one, so the series become

x , x-3 , x-6 , x-9, ............................

25 * m = 200

m =
`(200)/(25)`

m = 8

As m is the number of laps, and each lap is 3 second faster.

So 8 laps will be 8*3 = 24 seconds faster.