Answer:
The last answer; 12.
Step-by-step explanation:
In order to solve this, use substitution. Since it gives you an equation for y, substitute that equation in the other formula as y. This will give you:
Then simplify:
Since 6x - 6x cancels out, you are left with 12.
bus = (120/360) × 36
= 12 pupils
walk = (90/360) × 36
= 9 pupils