Question

A car leaves city A, at a speed of 90 km / h. Three hours later another car leaves the same city in search of the first one with a speed of 120 km / h. in which point do they meet?

Select the appropriate answer:
A) 120km
B) 30km
C) 1080km
D) 560 km

Please help! :(

Answer 1

The two cars will meet at a point 1080 km away from city A, after the second car travels for 9 hours at a speed of 120 km/h.

Step-by-step explanation:

To determine the meeting point of two cars, we must find out how far the first car travels before the second car catches up. The first car leaves at 90 km/h, and the second car leaves 3 hours later at 120 km/h.

The first car will have traveled 90 km/h × 3 h = 270 km before the second car starts. Since the second car is going 30 km/h faster than the first (120 km/h - 90 km/h = 30 km/h), we can calculate how long it will take for the second car to cover the initial 270 km gap.

Time = Distance / Relative Speed = 270 km / 30 km/h = 9 hours for the second car to catch up.

Now, we need to find the location at which they meet. We already know the second car travels for 9 hours at 120 km/h:

Distance = Speed × Time = 120 km/h × 9 h = 1080 km.

Therefore, the two cars meet at a point 1080 km away from the starting city, city A.

Answer 2

C) 1080km

Step-by-step explanation:

Let t be the time after A leaves

Distance covered by A:

90t

Distance covered by B:

120(t - 3)

90t = 120(t - 3)

90t = 120t - 360

30t = 360

t = 12

Distance: 90(12) = 1080