When the speed of a truck is increased by 20%, it takes 25 minutes less to cover the same distance. What is the time (in hours) taken to cover twice the distance at its actual speed?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 5.
Let original time = T
New time = T - = (T - )
Speed increased by 20%
⇒ S × T = 1.2S × (T − 5/12)
⇒ T = 1.2(T - )
⇒ T = 1.2T -
⇒ 0.2T = 0.5
⇒ T = 2.5 hours
Twice the distance = 2 × 2.5 = 5 hours