1987 AJHSME Problems/Problem 15

Problem

The sale ad read: "Buy three tires at the regular price and get the fourth tire for 3 dollars." Sam paid 240 dollars for a set of four tires at the sale. What was the regular price of one tire?

$\text{(A)}\ 59.25\text{ dollars} \qquad \text{(B)}\ 60\text{ dollars} \qquad \text{(C)}\ 70\text{ dollars} \qquad \text{(D)}\ 79\text{ dollars} \qquad \text{(E)}\ 80\text{ dollars}$

Solution 1

Let the regular price of one tire be $x$ . We are given:

$\begin{align*} 3x + 3 &= 240 \\ 3x &= 237 \\ x &= \boxed{\textbf{(D) 79}} \end{align*}$

Solution 2

To get the price, we can also work backwards without introducing a variable.

To get the price of all of the tires outside of the fourth tire, we can subtract $3$ from the total, which gives $240 - 3$ = $237$ .

Dividing this by $3$ to get the price of a single tire without the sale, we get:

$\frac{237}{3} = \boxed {\textbf {(D) } 79}$

1987 AJHSME (Problems • Answer Key • Resources)
Preceded by Problem 14	Followed by Problem 16
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25
All AJHSME/AMC 8 Problems and Solutions

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1987 AJHSME Problems/Problem 15

Contents

Problem

Solution 1

Solution 2

See Also