We know that:
- She has some of it complete, but the robot still needs 3 arms and 6 wheels.
- Patty has saved up $68, which is enough to buy the parts she needs.
- Arms costs $13 and wheels costs $4
We must find how much money is left after making the purchase.
To find it we must subtract the money spent on the purchase from the money saved.
- money spent:
Is the money spent when she buys the arms and the wheels
[tex]\text{ \$}13\cdot3+\text{ \$}4\cdot6=\text{ \$}63[/tex]So, the money spent is equal to $63
- money saved
Is the money Patty has saved.
Patty has saved up $68.
Finally, subtracting the money spent on the purchase from the money saved
[tex]\text{ \$}68-\text{ \$}63=\text{ \$}5[/tex]ANSWER:
After Patty buys the parts, $5 is left.
