Question

Two buses are moving towards each other, one at a speed of 40 mph and the other at a speed of 50 mph. In two hours two buses will become____ miles closer
PLZ answer it right no guessing

Answer 1

We know that
If the car travel in same direction,rel speed = v1 -v2, and if in opposite direction,rel speed = v1 + v2.
In this case

Relative speed = 40 + 50 = 90mph
Two buses will become close = distance travelled in 2hr= 90*2 = 180miles

Answer 2

Given :

The speed of first bus = $S_1$ = 40  mph

The speed of second bus = $S_2$ = 50 mph

Total time taken by both buses to moves towards each other = t = 2 hours

To Find :

The Distance cover by buses  

Solution :

Let The distance cover by first bus = $D_1$ miles

Let The distance cover by second bus = $D_2$ miles

∵  Time = $\dfrac{Distance}{Speed}$

For First bus

    t = $\dfrac{D}{S_1}$

Or,  2 hour = $\dfrac{D_1 miles}{40 miles per hour}$

∴  Distance = 2 h × 40 mph

i.e  Distance cover by first bus = 80 miles

Again

For Second bus

    t = $\dfrac{D}{S_2}$

Or,  2 hour = $\dfrac{D_2 miles}{50 miles per hour}$

∴  Distance = 2 h × 50 mph

i.e  Distance cover by second bus = 100 miles

Now,

The Distance between both the buses = $D_2$ - $D_1$

Or,                                                            = 100 miles - 80 miles

Or,                                                            = 20 miles

Hence, The two buses will become 20 miles closer to each other . Answer