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Problem of the Week
Problem A and Solution
Savings

Problem

Nethra is saving to buy a new gaming system. She needs $829 in total to buy the console. She has already saved $117.

Nethra has two part-time jobs. She works at a grocery store every Tuesday and Thursday for 2 hours each day. From the grocery store job she earns $15 per hour. She works at a restaurant every Saturday for 5 hours. From the restaurant job she earns $13 per hour.

Nethra gets paid every week on Sunday. That day she pays her parents $10 for transportation and buys herself $5 worth of treats. She saves the rest of the money she earned during the week.

How many weeks does Nethra have to work until she has saved enough money to buy the gaming system?

Solution

Since Nethra has already saved $117, she needs $829$117=$712 more to buy the gaming system.

From her job at the grocery store, she earns 4×$15=$60 each week.
From her job at the restaurant, she earns 5×$13=$65 each week.
This is a total of $60+$65=$125 each week.

Each week she spends $10+$5=$15.
This means she can save $125$15=$110 each week for the gaming system.

Now we can make a table to show how much she saves over multiple weeks:

Week Total Savings ($)
1 110
2 220
3 330
4 440
5 550
6 660
7 770

After 7 weeks Nethra has saved more than $712, so she has enough money to buy the gaming system.