sat math problem

<p>can anyone help me figure this out?</p>

<p>if a and b are integers such that a+b<1000 and a/b=.625, what is the greatest value of b?</p>

<p>the answer is supposed to be 608. I get how its done, the long way by subtracting multiples of 5 from 500 and 8 from 800.
but there must be a shorter way. </p>

<p>any ideas?
thanks</p>

<p>here's one way:</p>

<p>let a+b = 1000
a/b = .625</p>

<p>.'. b = 1000/1.625 = 615.384whatever</p>

<p>so the max value of b without the integer constraint is 615.3846blah
now its just a matter of finding highest multiple of 8 that's less than 615.</p>

<p>615/8 = 76.875
.875 * 8 = 7</p>

<p>.'. 615 -7 = 608 is the highest integer value for b.</p>

<p>cool. thanks again thekidhere</p>