Distance between A and B is 72 km. Two men started walking from A and B at the same time towards each other. The person who started from A traveled uniformly with average speed of 4 km/hr. The other man traveled with varying speed as follows: In the first hour his speed 2 km/hr, in the second hour it was 2.5 km/hr, in the third hour it was 3 km/hr, and so on. When / where will they meet each other?

Correct Answer: Mid-way between A and B
They covered the distance in this way together in different hours6 + 6.5 + 7 + 7.5 + 8 + 8.5 + 9 + 9.5 + 10 = 72Means,they'll meet at the 9th hr. So, In that time A will cover = 4 × 9 = 36kmThey will meet in Midway