Question

Emily ran her first lap in 75 seconds. She ran her second lap in 69 seconds. Using percentages, how much better was her second lap when compared to her first lap?

Answer 1

Answer:

8%

Step-by-step explanation:

Emily ran her first lap in 75 seconds.

She ran her second lap in 69 seconds.

The difference = 75 - 69 = 6 seconds.

The percentage of difference = 6/75 = 0.08 = 0.08 *100% = 8%

So, her second lap is better than her first lap by 8%

Answer 2

For this case we propose a rule of three:

We have that 75 seconds of the first lap equals 100%, so we find the percentage of the second lap:

75 s -------------> 100%

69 s --------------> x

Where the variable "x" represents the percentage of seconds associated with Emily's second lap.

$x = \frac {69 * 100} {75}\\x = \frac {6900} {75}\\x = 92$

Thus, on the second lap he ran 8% better than the first.

Answer:

According to lap time, the second lap was 8% better than the first.