Question

5
82. A car travelling with 5/7
of its actual speed covers
42 km in 1 hr 40 min 48 sec. Find the actual speed
of the car.
(S.S.C., 2005)
6
(a) 17 km/hr
(b) 25 km/hr
7
(c) 30 km/hr
(d) 35 km/hr
7​

Answer 1

Answer:

1 hr = 60 min

1 min = 60 secs

So start with 48 secs first which is 48/60 min = 0.8 min

Now, it is 1 hr 40.8 min.

40.8/60 = 0.68 hr

So the time covered is 1.68 hrs.

speed = distance/time

(5/7)*actual speed = 42 km / 1.68 hr

(5/7)*actual speed = 25

actual speed = 25*(7/5) = 35 km/hr