Question

A car travelling at 60km/hr left Dehradun at 3p.m . One hour later , another car travelling at 80km/hr started over the same road to overtake the first , how long must the second car travel to overtake the first car

Answer 1

One hour later another car ...

Let x and (x+1)represent the times of the second and first car respectively

Question states*** Note: d = r*t, distance the same for both cars

60kmph(x+1) = 80kmph*x |Note: using kmph for both, assuming typo

Solving for x

60kmph = 20x

3hr = x , time of the second car traveling 80kmph

CHECKING our Answer***

4hr*60kmph = 80kmph*3hr = 240km

Answer 2

▶ Answer:-

→ 3 hours and 240 km .

▶ Step-by-step explanation:-

→ Let the time taken by second car overtake to the first car be x hours after it started.

→ Total time taken by first car = (x + 1) hours.

→ Total distance covered by first car in (x + 1) hours = 60(x + 1) km .

→ Distance covered by second car in x hours = 80x .

Thus, Distance coved by first car is equal to second car .

∴ 60(x + 1) = 80x .

⇒ 60x + 60 = 80x .

⇒ 60 = 80x - 60x .

⇒ 60 = 20x .

⇒ $\bf{\dfrac{60}{20}}$ = x

∴ x = 3 .

Hence, the second car travelled in 3 hours to overtake the 1st car .

→ Therefore, time taken by second car to overtake the first car = 80x = 80 × 3 = 240 km.

✔✔ Hence, it is solved ✅✅.