Answer: 13 weeks.
Step-by-step explanation:
Every number seems to be tripled:
we have that:
Antonia needs to have worked at least 90 volunteer hours.
She already has worked 52 hours over the summer
She needs to work 3 hours per week to complete her remainder, we want to find how many weeks she needs to work.
the hours that she needs to work are:
90 - 52 = 38
she needs to work 38 hours, then, at a rate of 3 hours per week we have that:
w = 38/3 = 12.67
but we need to round up this, so we would have 13 weeks.
and she will work a total of 3*13 = 39 hours, plus the 52 that she already had this ad to 91 hours, so she will complete the minimum of 90 hours.