Question

The school hockey team travelled 150 km to a tournament by bus. The bus drove at 90 km/h for most of the way, but was delayed by a storm, when its speed was only 30 km/h. If the trip took 3 hours, how far did the bus travel in the storm

Answer 1

90a + 30b = 150
a + b = 3
30a + 30b = 90
-(90a + 30b = 150)
-60a + 0 = -60
a = 1
a + b = 3
1 + b = 3
b = 2
so they travelled 1 hour at 90k and 2 hours in the storm at 30k

Answer 2

Answer:

The bus traveled 1 hour at 90 km/h and 2 hours in the storm at 30 km/h

Explanation:

From the example, let us recall the following statements

The school hockey team traveled 150 km to a tournament by bus.

The bus drove = 90 km/h for most of the way

The speed was only 30 km/h. when delayed by a storm

Now, lets find how far the bus travel in the storm

Given that

90x + 30y = 150

x+ y = 3

30x + 30y = 90

-(90x + 30y = 150)

-60x + 0 = -60

so,

 x = 1

 x + y = 3

 1 + y = 3

  y = 2

Therefore, they travelled 1 hour at 90km/h and 2 hours in the storm at 30km/h