Speed of the first car is 30 mph and that of the second car is 20 mph.
Step-by-step explanation:
- Step 1: Let the speed of the first car be x mph. Then the speed of the second car = x - 10 mph. Distance traveled by the second car = 60 miles. Find the time taken by the second car to travel this distance.
Time = Distance/Speed
= 60/x - 10 ------ (1)
- Step 2: Find the time taken by the first car to travel given distance of 90 miles.
Time = 90/x ------- (2)
- Step 3: Given that both cars take the same amount of time, equate the 2 equations. (1) = (2)
⇒ 60/x - 10 = 90/x
⇒ 60x = 90(x-10)
⇒ 2x = 3(x - 10)
⇒ 2x = 3x - 30
⇒ -x = -30
∴ x = 30 mph
⇒ x - 10 = 30 - 10 = 20 mph
