a person walks at a speed of 4 km / hr and runs at a speed of 8 km / hr . how many hours will the person require to cover a distance of 8 km , if the person completes half of the distance by walking and the other half by running ?
"time = 4 / 4 + 4 / 8 = 12 / 8 = 1.5 hours the answer is b ."
add(divide(divide(8, const_2), 4), divide(divide(8, const_2), 8))