If 3 pencils cost $0.75, how much do 5 pencils cost?

To find the cost of 5 pencils, we can set up a proportion using the given information. Let's represent the cost of 5 pencils as "x".

We can use the following proportion:

[ \frac{3 \text{ pencils}}{0.75} = \frac{5 \text{ pencils}}{x} ]

Cross multiplying, we get:

[ 3x = 0.75 \times 5 ]

Solving for x:

[ x = \frac{0.75 \times 5}{3} = $1.25 ]

So, 5 pencils cost $1.25.