For the a we have that the answer is
[tex]x\text{ }\ge\text{ 12}[/tex]
For the b. we have that the answer is
[tex]x\text{ }\ge\text{ 15}[/tex]
Because in the part a. we have an equation where the x represents ths amount of people that are in the bus, and only 3 people more get on the bus, like no one get off, we only need to add the number of people that at least are on the bus.
