# Find the Distance, in Kilometer, Between P and Q :

A man starts from a place P and reaches the place Q in 7 hours. He travels of 1/4^{th} of the distance at 10 km/hour and remaining distance at 12 km/hour. The distance, in kilometer, between P and Q is

- 80
- 72
- 70
- 90

**Answer is (1): 80**

**Explanation:-**Let the total distance be X km

Total time taken by a man = 7 hours

According to the question,

(X/4)/10 + (3 X/4)/12 = 7

X/40 + 3 X/48 =7

(48 X + 120 X)/1920 = 7

168 X = 7 x 1920

X = 7 x 1920/168

X = 1920/24

X = 28 km

Then, the distance between P and Q is 28 km.

Hence, the answer is (1) 80.