GMAT Practice Question: The toll T, in dollars, for a truck using a certain bridge is given by the formula T=1.50+...
Question
The toll T, in dollars, for a truck using a certain bridge is given by the formula T=1.50+ 0.50(x-2), where x is the number of axles on the truck. What is the toll for an 18-wheel truck that has 2 wheels on its front axle and 4 wheels on each of its other axles?
- $ 2.50
- $ 3.00
- $ 3.50
- $ 4.00
- $ 5.00
Topics: word problems, function variable substitution
Solution
Step 1
We name x the number of axles on the truck.
x=\text{number of axles on the truck}
Step 2
We calculate the number of axles by accounting for the front wheels and dividing the remaining wheels by the number of wheels per axle.
18-2=16 \frac{16}{4}=4 x=1+4=5
Step 3
We substitute x=5 into the toll formula and simplify.
T=1.50+0.50(x-2) T=1.50+0.50\times(5-2) T=1.50+0.50\times3 T=1.50+1.50=3.00
Answer
3.00
