Question

Pooja covers a distance of 1200 km in 70 days resting 9 hours a day, if she rests 10 hours a day and walks with speed 1(1/2) times of the previous speed, then in how many days will she cover 840 km?
1. 35 Days
2. 30 Days
3. 25 Days
4. 45 Days
5. None of these 

Answer 1

Correct Answer - Option 1 : 35 Days

Given:

Distance = 1200 km

Formula:

Speed = Distance/Time

Calculations:

Let S be the speed

She walks = 24 – 9

⇒ 15 hours a day

So, totally she walks for 70 × 15

⇒ 1050 hrs.

S = 1200/1050

⇒ 120/105 = 24/21

⇒ 8/7 kmph

New speed is 1(1/2) of previous speed

⇒ 3/2 × 8/7 = 24/14 = 12/7

New speed = 12/7 kmph

Now he rests 10 hrs a day that means he walks

⇒ 24 – 10 = 14 hrs a day.

Time = 840 × (7/12)

⇒ 490 hrs

⇒ 490/14 = 35 days

∴ Pooja will take 35 days to cover 840 km.