Question

Carina has $100$ ounces of coffee divided into $5-$ and $10-$ ounce packages. If she has $2$ more $5-$ ounce packages than $10$-ounce packages, how many $10$-ounce packages does she have?

• A. $4$
• B. $5$
• C. $7$
• D. $6$

Answer 1

Answer: (D)

$6$

Let $a=$ the number of $5-ounce$ packages.

Let $b=$ the number of $10-ounce$ packages.

From the given question, 2 equations can be derived:

5a + 10b = 100

a = b + 2

Combine the equations by substituting the value of $a$ from equation $2$ into equation $1$:

$5(b+2)+10b=100$

$5b+10+10b=100$

$15b+10=100$

$15b=90$

$b=6$