Official Guide problem

Hi Joy Shaha,

This prompt gives us a formula that is based on the number of truck AXLES. Once we know the number of axles, we can figure out the total price of the toll.

We're told that that a truck has 18 wheels --> 2 wheels on the front axle and 4 wheels on each of the other axles. With that information, we know that there are 5 total axles:

1st axle = 2 wheels
2nd axle = 4 wheels
3rd axle = 4 wheels
4th axle = 4 wheels
5th axle = 4 wheels
Total = 18 wheels

Since the truck has 5 axles, we can plug in X=5 into the given equation...

T = 1.50 + (.50)(5-2) = 1.50 + (.50)(3) = $3.00

Final Answer: B

GMAT assassins aren't born, they're made,
Rich

Joy Shaha wrote: ↑

Fri May 20, 2016 1:20 am

Q. Source: GMAT Official (2016)
Q. The toll T , in dollars fir a truck using a certain bridges is given by the formulate T=1.50+.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 the front axle & 4 wheels on each of its other axles ?
A. $ 2.50;
B.$ 3.00
C.$3.50;
D.$4.00
E.$ 5.00

We need to determine the toll for an 18-wheel truck that has 2 wheels on its front axle and 4 wheels on each of its other axles.

Since there are 18 wheels and 2 wheels on the front axle and 4 wheels on the other, we have 1 axle for the front 2-wheels and 16/4 = 4 axles for the other wheels. Thus, the truck has a total of 5 axles and its toll is:

T = 1.5 + 0.5(5 - 2)

T = 1.5 + 1.5 = 3.00

Answer: B