Two men start together to walk to a certain destination, one at 3.75 km an hour and another at 3 km an hour. The former arrives half an hour before the latter, the distance is?
Correct Answer: 7.5 km.
Explanation:
Let the distance be y km.
From question
y/3 - y/3.75 = 1/2
⇒ (3.75y - 3y) / (3 x 3.75) = 1/2
⇒ 1.5y= 3 x 3.75
∴ y = ( 3 x 3.75 ) / 1.5
= 7.5 km.
