BTGmoderatorLU wrote:If the ratio of the present age of Anna and Paula is 3 : 4, what could be the ratio of their respective ages after 8 years?
A. 1 : 2
B. 3 : 8
C. 3 : 5
D. 2 : 3
E. 4 : 5
The OA is E.
Source: e-GMAT
Here's a nice property of fractions:
If a, b and k are positive, then (a + k)/(b + k) approaches 1 as k gets bigger.
For example, the fraction (2+11)/(3+11) is closer to 1 than 2/3 is.
Likewise, the fraction (1+7)/(2+7) is closer to 1 than 1/2 is.
Let A = Anna's present age
Let P = Paula's present age
So,
A/P = 3/4
In EIGHT YEARS, we can conclude that:
Let A + 8= Anna's future age
Let P + 8 = Paula's future age
So, in EIGHT YEARS, the ratio of their ages = (A + 8)/(P + 8)
By the above
rule, we know that (A + 8)/(P + 8) is closer to 1 than is
A/P is.
In other words, (A + 8)/(P + 8) is closer to 1 than
3/4 is.
Check the answer choices.....
Only answer choice E (aka 4/5) is closer to 1 than
3/4 is.
Answer: E
Cheers,
Brent
