Ruby has a goal to save $170 by the end of the summer. She has already saved $50, and is selling drawings she has made for $10 each. How many drawings does she need to sell to save exactly $170?

Question

Let d be the number of drawings Ruby sells. Start by writing an expression that represents the total amount of money Ruby has after selling d drawings.
Good work!
Complete the equation to represent the amount of money Ruby wants to save.
10d+50 =
Nice!
Solve for the value of d. Solve on paper, or show your work below. Then enter your answer on Zearn.
10d+50
=
170

d
=
Great job!
What does your answer of 12 mean in this situation?
10d+50 = 170
d = 12

Ruby needs to sell 12 drawings in order to save $170.

Ruby needs to sell the drawings for $12 in order to save $170.

Ruby needs to make $12 more to save $170.
Excellent!
Let’s say that Ruby wants to save at least $170. Complete the statement to write an inequality that represents Ruby saving at least $170.
10d+50 = 170
d = 12

10d+50
≥
170
Nice!
Write the solution to the inequality.
10d+50 = 170
d = 12

10d+50 ≥ 170
d
12

Answer 1

To solve the inequality \(10d + 50 \geq 170\), we can follow these steps:

1. Subtract 50 from both sides: \[ 10d \geq 170 - 50 \] \[ 10d \geq 120 \]

2. Divide both sides by 10: \[ d \geq \frac{120}{10} \] \[ d \geq 12 \]

Thus, the solution to the inequality is: \[ d \geq 12 \]

Interpretation:

This means Ruby needs to sell at least 12 drawings to save at least $170. If she sells exactly 12 drawings, she will have exactly $170 saved. If she sells more than 12 drawings, she will save more than $170.