Rewrite 15 1/4% as 15.25%. To obtain the desired fraction, divide this 15.25% by 100%:
0.1525
This could be reduced to 61/400, which was obtained by first writing 0.1525 as 1525/10000.
The answer is actually 80 degrees, I just took the test.
<span>let x be the interval, then:
186 = 50 + 3 + (3+x) + (3+2x) + (3+3x) + (3+4x) + (3+5x) + (3+6x) + (3+7x)
186 = 74 + 28x
x = 4
Eldest son age = 3+7x = 3+28 = 31.</span>