Question

Carli made 9 greeting cards in 3/4 hour. She determined her unit rate to be 1/12 card per hour. Find her error and correct it.

a. Carli made 12 greeting cards in 3/4 hour.
b. Carli made 8 greeting cards in 1 hour.
c. Carli made 12 greeting cards in 1 hour.
d. Carli made 9 greeting cards in 1/12 hour.

Answer 1

Carli incorrectly calculated her unit rate of making greeting cards. The correct unit rate is found by dividing the number of cards (9) by the time in hours (3/4), resulting in 12 cards per hour. The correct answer is that c. Carli made 12 greeting cards in 1 hour.

Step-by-step explanation:

The question involves finding the correct unit rate of greeting cards that Carli made in a given amount of time. To find the unit rate, we divide the number of cards by the time it took to make them, converting the time into hours if necessary.

Since Carli made 9 greeting cards in 3/4 hour, we calculate the unit rate by dividing 9 by (3/4), which simplifies to 9 divided by 0.75.

Here is the calculation: 9 ÷ (3/4) = 9 ÷ 0.75 = 12.

Therefore, Carli's unit rate is 12 cards per hour, not 1/12 card per hour as she initially determined. Among the options provided, the correct answer is (c) Carli made 12 greeting cards in 1 hour.