A math prob. Pls help me

[tracyyahoo]

If 1/4 of the larger of two numbers is greater than 5 times the smaller of the same two numbers, is the smaller number less than 4?

(1) The larger number is greater than 70?
(2) The larger number is less than 80.

I chose C why the hell is B

[Anurag@Gurome]

If 1/4 of the larger of two numbers is greater than 5 times the smaller of the same two numbers, is the smaller number less than 4?

(1) The larger number is greater than 70?
(2) The larger number is less than 80.

I chose C why the hell is B

Let the larger number = L and smaller number = S
If L/4 > 5S, then is S < 4?

(1) L > 70
If L = 72, then S < 18/5 or S < 3.6; in this case S < 4 holds true.
If L = 84, then S < 21/5 or S < 4.2; in this case S < 4 does not hold true.
Since we do not get a definite answer; NOT sufficient.

(2) L < 80
If L = 79.8, then S < 19.95/5 or S < 3.99, which implies S < 4 will always hold true; SUFFICIENT.

The correct answer is B.