Question

Suppose two swimmers jump in from opposite sides of a swimming pool, and begin to swim towards each other. If one swimmer swims at a rate of 70 meters per minute, and the other swims at a rate of 80 meters per minute, and the pool is 480 meters long, how long before they bump heads?

Answer 1

They will bump heads at 3.2 minutes

Explanation:

Here, we want to calculate the time taken for them to meet at a point.

Let the distance traveled by the first swimmer be x, it means the second swimmer will meet the first swimmer at the point (480 - x)

The time taken for the first swimmer will be;

distance/ speed

= x/70

For the second swimmer, his time will be ;

(480-x)/80

Since we know the time they meet will be equal;

Then we equate both times;

x/70 = (480-x)/80

Cross multiply

80x = 70(480-x)

80x = 33600 - 70x

80x + 70x = 33,600

150x = 33,600

x = 33600/150

x = 224

So the time will be;

224/70 or (480-224)/80

= 3.2 minutes