distance problem

Quote:

Originally Posted by sri340

Mary walked 4 laps around the park track. It took Mary 4 minutes to walk the first lap. The second lap took 25% longer than the first lap. The third lap took 20%
longer than the second lap. The final lap took 50% longer than the third. What was
Mary’s total walking time for the 4 laps?

Lap 1 took 4 mins.
Lap 2 took 4+0.25(4)=4+1=5 mins
Lap 3 took 5+0.2(5)=5+1=6 mins
Lap 4 took 6+0.5(6)=6+3=8 mins

Total time = 4+5+6+8 mins

A percentage is expressed in English using only the numerator of the fraction.

25%= $\frac{25}{100}=0.25$

20%= $\frac{20}{100}=0.2$ etc