Question

A child bus ticket costs $0.40 and an adult’s ticket costs $0.70. A group of 11 individuals pays $5.90 for their fare.
Quantity A
The number of children

Quantity B
The number of adults


which one is bigger? A or B?

Answer 1

Here we have a system of equation like this:
$A+B=11\\ 0.4A+0.7B=5.9$
from the first equation we get:
$A=11-B$
Substitute in the second equation we get:
$0.4(11-B)+0.7B=5.9\\4.4-0.4B+0.7B=5.9\\0.3B=1.5\\B= \frac{1.5}{0.3}=5$
Substitute i the first equation again we get:
$A=11-B=11-5=6$
We deduce that:
$A > B$ A is bigger than B.