Question

10. A car takes 2 hrs to reach a place by travelling at
the speed of 60 km/h. How long will it take when
car travels at the speed of 80 km/h? [AMU:2016-17)
a)1 hour
b )1/2 hour
c)1 1/2 hour
d) 2 hour.
​

Answer 1

So the answer is c) 1 1/2 hours

Explanation;-
Given :-
Speed 60 km/h
Time :- 2 hours
Distance :- 60 x 2 = 120 km
So
No the car is covering the same distance
Speed = 80 km/h
Distance = 120 km
Time = Distance/ speed
Time= 120/80
3/2 hours

Answer 2

Question:-

A car takes 2 hrs to reach a place by travelling at

the speed of 60 km/h. How long will it take when

car travels at the speed of 80 km/h?

Solution:-

Given,

• A car takes 2 hours to reach a place at a speed of 60km/h.
• If it travels with a speed of 80km/h then how much time it takes.
• Here we know that as the speed increases automatically time will be decreased.

So,

➣ 60 × 2 = 80 × x

➣ x = 120/80

➣ $\boxed{ \: x \: = \: \frac{3}{2} }$

Then,

∴ The speed the car should have to cover a distance is 3/2 or 1¹/5 hours.

Verification:-

➣ 60 × 2 = 80 × x

➣ 120 = 80 × 3/2

➣ 120 = 40 × 3

➣ $\boxed{ \: 120 \: = \: 120\: }$