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Last Updated on May 11, 2023
GMAT OFFICIAL GUIDE PS
Solution:
We are given that the product of two negative numbers is 160 and that the lesser of the two numbers is 4 less than twice the greater.
We can let x = the larger number and y = the smaller number, and we can create the following equations:
(x)(y) = 160
AND
y = 2x – 4
Substituting (2x – 4) for y in the first equation yields:
x(2x – 4) = 160
2x^2 + 4x = 160
x^2 – 2x – 80 = 0
(x – 10)(x + 8) = 0
x = 10 or x = -8
Since x is negative, x = -8 and y = 2(-8) -4 = -20.
Thus, the greater number is -8.
Answer: D
