If Angela is twice as old as the combined ages of Bill and Charlie

Question

If Angela is twice as old as the combined ages of Bill and Charlie, then how old is Charlie?

(1) Four years from now, the sum of all three people’s ages will be 108.

(2) Five years ago, the average (arithmetic mean) of all three people’s ages was 27.

This is a  Data Sufficiency Butler Question

Check the links to other Butler Projects:

Problem Solving Butler  
  Data Sufficiency Butler  
  Critical Reasoning Butler  
  Reading Comprehension Butler  
  Data Insights Butler

dhart · Answer

premise a = 2(b+c)
stmt 1 : Four years from now, the sum of all three people’s ages will be 108
a+4+b+4+c+4= 108, a+b+c= 96 , with premise a = 64
combined age of bill and charlie can be known , insuff

stmt 2: Five years ago, the average (arithmetic mean) of all three people’s ages was 27
a+b+c = 81+15 = 96, alongwith premise same as stmt1 , insuff

stmt 1 + 2 :

same as stmt 1 and 2 looks insuff
 i thinks option E

HarishChaitanya · Answer

the most common mistake of mine, i quickly thought after looking at statements 1&2 is we have got two equations which has two variables, hence can be solved. And i quickly chosen c as option.

but, the trap is both statement 1&2 are giving same equations. therefore can not be solved when put together.

hence E is the ans.

please take a few more seconds to verify your answers

odionam · Answer

St 1 as well as 2 both have the same equation sum is 108-12 =96 current age sum 
similarly St2 27*3+15= 96 current sum of all three's age is 96
 so we can't calculate single person age from any given statement so E is answer

Beowulf2nd · Answer

Correct answer is D.
Both statements are individually sufficient.

A = 2(b+c)

Statement 1:
A+B+C+12 = 108  A+B+C = 108-12 = 96 
96/4 = 24
A = 48
B = 24
C = 24

Statement 2:
A+B+C-15/3 = 27  A+B+C = (27x3)+15 = 96 
96/4 = 24
A = 48
B = 24
C = 24

Beowulf2nd · Answer

Correction:
 Correct answer is E.
Because we are dealing with the sum and the average, we do not know if B and C have necessarily the same age.
They could be 25 + 23 - 28 + 20.

Mehta17 · Answer

By statement 1 and 2, we can get that the current ages sum for the three people is 96 but we cant get the age of Charlie

If Angela is twice as old as the combined ages of Bill and Charlie

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Data Sufficiency (DS) Questions

­If Angela is twice as old as the combined ages of Bill and Charlie

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

If Angela is twice as old as the combined ages of Bill and Charlie