The amount of money Joaquin took out of his bank account in January is shown on the vertical number line below.

Question

A point is 20 units below 0.

Joaquin then added $65.71 to his account in February. What was the overall change in Joaquin’s bank account for January and February combined?

A.
−
$
85
.
71

B.
−
$
45
.
71

C.
$
45
.
71

D.
$
85
.
71

Answer 1

To find the overall change in Joaquin's bank account for January and February combined, we need to determine his bank account changes for each month.

1. January: The problem states that the point is 20 units below 0, which means Joaquin took out $20. Therefore, for January, the change is: \[ \text{Change in January} = -20 \]

2. February: Joaquin added $65.71 to his account, which means for February, the change is: \[ \text{Change in February} = +65.71 \]

3. Overall Change: Now to find the overall change in his bank account for January and February combined, we add the changes from both months: \[ \text{Overall Change} = \text{Change in January} + \text{Change in February} \] \[ \text{Overall Change} = -20 + 65.71 \] \[ \text{Overall Change} = 45.71 \]

So the overall change in Joaquin's bank account for January and February combined is:

\[ \text{Overall Change} = $45.71 \]

Thus, the correct answer is:

C. $45.71