The time taken by Jill to swim one lap is 40 seconds and this can be determined by using the unitary method.
Given :
- Jill swam 200 meters in 2 minutes 42 seconds.
- Each lap is 50 meters long.
The following steps can be used in order to determine the time taken by Jill per lap:
Step 1 - Remember 1 minute is equal to 60 seconds.
Step 2 - Convert 2 minutes 42 seconds in seconds. If in 1 minute there are 60 seconds then in 2 minutes there are 120 seconds.
Step 3 - So total time taken to cover 200 m is:
= 120 + 42
= 162 seconds
Step 4 - Now, if Jill swam 200 m in 162 seconds then the time taken by Jill to swim 50 m is:
[tex]=\dfrac{50}{200}\times 162[/tex]
Step 5 - Simplify the above expression.
= 40.5 seconds
Therefore, the correct option is B).
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https://brainly.com/question/23423168
