Question

The time t , it takes for omar to drive the distance d , to his grandmothers house is inversely proportional to his average rate of speed ,r it takes omar 2.5 hours to get to his grandmothers house if he drives at an average speed of 30 miles per hour. how long will it take him if he drives at an average speed of 50 miles per hour

Answer 1

$d=tr\\\\\text{we have}\\\\t_1=2.5\ h\\r_1=30\ mph\\r_2=50\ mph\\\\\text{substitute}\\\\50t_2=2.5\cdot30\\50t_2=75\ \ \ |:50\\t_2=1.5\ h$

Answer: 1.5 hours.