Chapter 1.2, Problem 37E

To determine

To write and solve a equation according to the given statement

Answer to Problem 37E

One taco costs $3.75

Explanation of Solution

Given:

The cost of a salad = $2.50

Also, 8% tax was paid and a tip of $3 was left.

The total payment was $13.80.

Calculation:

Let, the cost per taco be $ x .

Now, if 2 tacos and a salad were bought, total cost will be = $( 2x + 2.50)

After adding 8 % tax the cost becomes = $(( 2x + 2.50) + 8% of ( 2x + 2.50))

= $(( 2x + 2.50) + 0.08 of ( 2x + 2.50))

= $( 2x + 2.50)(1 + 0.08)

= $( 2x + 2.50) ×1.08

After adding tip to the cost the final total cost paid becomes = $(( 2x + 2.50) × 1.08 + 3)

According to the statements,

  $\begin{array}{l}\Rightarrow (2x+2.5)\times 1.08+3=13.80\\ \Rightarrow \frac{2x+2.5}{1.08}=\frac{10.8}{1.08}\\ \Rightarrow x=\frac{10-2.5}{2}\\ \Rightarrow x=3.75\end{array}$

Conclusion:

Hence, the cost of per taco is $3.75.