Question

max is training for a triathlon. he recorded the time for each portion of the race during his practices. max wants to know which event had the most improved time.
triathlon event | maxs first practice time (min) | maxs last practice time (min) | amount of change (min) | percent decreas
running (10 k) | 80 | 68 | 12 | 15
swimming (1.5 k) | 60 | 48 | 12 | 20
biking (40 k) | 90 | 81 | 9 |
what is the percent decrease in maxs biking time?
%

Explanation:

Step1: Recall percent decrease formula

Percent Decrease = $\frac{\text{Amount of Change}}{\text{First Practice Time}} \times 100\%$

Step2: Plug in biking time values

$\frac{9}{90} \times 100\%$

Step3: Calculate the percentage

$0.1 \times 100\% = 10\%$

Answer:

10%