1.  A is faster than B. A and B each walk 24 km. The sum of their speeds is 7 km/hr and the sum of times taken by them is 14 hours. Then, A's speed is equal to :
A. 3 km / hr
B. 4 km / hr
C. 5 km / hr
D. 7 km / hr

Answer: Option B

Explanation:

Let A's speed = x km / hr.
Then, B's speed = (7 - x) km / hr.
So, 24/x + [2 4 / (7 - x ) ] = 14

<=> 24 (7 - x) + 24x = 14x (7 - x)
<=> 14x2 - 98x + 168 = 0
<=> X2 – 7x + 12 = 0
<=> (x - 3) (x - 4) = 0
<=> x = 3 or x = 4.

Since, A is faster than B, so A's speed = 4 km / hr
and B's speed = 3 km / hr.