Hey guys,
I'm studying for the gre and am wondering if there's any trick to solving a problem like this w/o doing the actual math:
Which is greater:
210,000 X 95,250
or
210,250 X 95,000
What is the general trick?
Thanks!
Hmm. Generally, I'd say that you're looking at an extremum problem, essentially. You're looking at the product of two numbers, x * y, such that x + y = const. It's like maximizing the area of a rectangle given that the perimeter is constant. What's your gut instinct?
Hello, sfspitfire23!
Which is greater: .[1] 210,000 × 95,250 .or .[2] 210,250 × 95,000 ?
We have:
[1] (210,000) × (95,000 + 250) . and .[2] (210,000 + 250) × (95,000)
Let: .x = 210,000, .y = 95,000
Then we have: .x·(y+250) .[?] .(x+250)·y
. . . . . . . . . . . xy + 250x .[?] .xy + 250y
. . . . . . . . . . . . . . .250x .[?] .250y
. . . . . . . . . . . . . . . . . x .[?] .y
Since x > y, then: .[1] .> .[2]