Answer: 30 hours (choice B)
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Step-by-step explanation:
If he gets 15% off, then he pays the remaining 85%. Notice how 15+85 = 100. Or you could say 100-15 = 85.
The phone will cost 0.85*750 = 637.50 dollars after the discount. This is before taxes and/or other possible fees.
He has $200 saved and makes $15 an hour. If x is the number of hours he works, then his bank balance is 15x+200 dollars.
Set this equal to the 637.50 value found earlier and solve for x.
15x+200 = 637.5
15x = 637.5-200
15x = 437.5
x = 437.5/15
x = 29.16667 approximately
If Pete works for 29 hours, then,
15x+200 = 15*29+200 = 635
He's coming up a bit short.
But if he works for 30 hours, then,
15x+200 = 15*30+200 = 650
and now he is over the threshold of $637.50
Therefore, he needs to work 30 hours.