Answer:
7 7/12
Step-by-step explanation:
Find the amount of rolls in all that were donated:
60 x 12 = 720.
The total amount used is 679. Subtract 679 from 720:
720 - 629 = 91.
Find the amount per dozen. Divide 91 with 12:
91/12 = 7 7/12
7 7/12 is your answer.
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Step-by-step explanation:
2x = x1.2^n
2 = 1.2^n
log1.2(2) = n
log10(2)/log10(1.2) = n = 3.801784017...
so, rounded to the next whole year it takes 4 years.