If a race car can go around a track in 5 minutesthen how lon

If a race car can go around a track in 5 minutes,then how long will it take to go around the track if it increases its speed by 20%?

Solution

v=d/t
.
(1) v=d/5
.
(2) 1.2 v = d/t
.
from (2),,v=d/(1.2 t) = d /5,,,,,,from(1)
.
1.2 t =5
.
t= 5/1.2 = 4.17 min
.
checking,,,,let d=10, v= 10/5 =2
v2= 10/4.17 = 2.4
.
2.4 / 2 = 1.2,,,or 20 % higher