Question 222773
The gym is 21 years newer than the Auditorium. The gym is also one fourth as old as the Auditorium. How old is each building?
Choices for the Auditorium: 26, 27, 28
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Let G = age of gym
and A = age of auditorium
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The gym is 21 years newer than the Auditorium.
G = A-21 (equation 1)
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The gym is also one fourth as old as the Auditorium.
G = (1/4)A (equation 2)
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Substitute the value of 'G' from equation 1 and plug it into equation 2 and solve for A:
A-21 = (1/4)A 
4A - 84 = A
3A = 84
A = 28 years  (age of auditorium)