A bus with a capacity of 33 people and a matatu with a capacity of 11 people transported a total of 319 people. The matatu made one extra trip than the bus. How many people did the matatu transport?

Let $B$ be the number of trips made by the bus.
Let $M$ be the number of trips made by the matatu.

The bus has a capacity of 33 people.
The matatu has a capacity of 11 people.
The total number of people transported is 319.
So, the total people transported can be expressed as:

The matatu made one extra trip than the bus:

Substitute $M = B + 1$ into $33B + 11M = 319$:

Using $M = B + 1$:

The matatu transported 11 people per trip and made 8 trips.
Number of people transported by matatu = $11 \times M$

The matatu transported 88 people.