Speed of the car is 45 km/h
Step-by-step explanation:
- Step 1: Find the distance traveled by the car in the first case.
Given that the speed of the car = 10 (t + 3) km/h
Time taken = 4 (t + 3) hours
Distance = Speed × Time
= 10 (t + 3) × 4 (t + 3) = 40(t + 3)² km
- Step 2: Equate the distance of 810 km with the distance that has been calculated above, since both are the same.
⇒ 810 = 40 (t + 3)²
⇒ (t + 3)² = 81/4
⇒ t + 3 = √81/4 = 9/2
⇒ t = 9/2 - 3 = 3/2 = 1.5
- Step 3: Find the speed of the car.
Speed = 10 (1.5 + 3) = 10 × 4.5 = 45 km/h
