The number of hours each sibling must work each week to reach their goal of $224.50 is as follows:
The total amount of money that needs to be saved = $224.50
Total amount of money Nancy earn = $10.70 per hour.
Total amount of money Marc earn = $11.30 per hour
Total amount of money Kara earn = $9 per hour
Number of hours Nancy works = X hours
Number of hours Marc works = 5 + X hours
Number of hours Kara works = X - 2 hours
To calculate the amount each earn according to the number of hours they worked the following is carried out;
10.70(X) + 11.30( 5+X) + 9(x-2) = 224.50
10.70x + 56.5 + 11.30x + 9x - 18 = 224.50
Collect the like terms together
10.70x+11.30x+9x +56.5-18 = 224.50
31x + 38.5 =224.50
31x =224.50 - 38.5
31x = 186
X = 186/31
X = 6
Therefore Nancy works for 6 hours
Marc works for 5 + X = 5+6 = 11 hours
Kara works for x- 2= 6-2 = 4 hours
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