math
posted by Anonymous .
if 1.5 teens eats 1.5 pizzas in 1.5 hours, how many pizzas can 9 teens eat in 6 hours? How do I do this problem, not just the answer. Thanks

Each teen requires 1.5 hours per pizza, since 1.5 teens eat 1.5 in that time. In six hours, each teen can eat four, assuming that their degree of hunger and stomach capacity remains the same. Nine teens can therefore eat 36.

I like doing these questions the following way:
keeping the time constant:
1.5 teens eats 1.5 pizzas in 1.5 hours
3 teens eats 3 pizzas in 1.5 hours
9 teens eats 9 pizzas in 1.5 hours
now keep the teens constant:
9 teens eats 9 pizzas in 1.5 hours
9 teens eats 18 pizzas in 3 hours
9 teens eats 36 pizzas in 6 hours
as can be seen in drwls' answer.