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sri340
Average Member

USA
18 Posts

 Posted - 11/13/2008 :  07:41:13 Average age of A & B is 24 years and average of B, C & D is 22 years. The sum of the ages A, B, C & D is a)90 years b) 96 years c)114 years d)data inadequate

Haven
Senior Member

USA
28 Posts

 Posted - 11/13/2008 :  11:37:28 To solve this problem you must have an understanding of what an average is and know how to use the average formula.To solve this problem: The first step is to find the value of A or B. The problem tells you that the average of A + B equals 24; by using the average formula this means that A + B divided by 2 equals 24, or multiplying both sides by 2 gives you A + B equals 48. the average value of A or B equals 24.The second step is to substitute 24 into the second average problem of (B) + C + D = 22; this means that 24 + C + D divided by 3 equals 22, or multiplying both sides by 3 gives 24 + C + D = 66. Subtracting 24 from each side now gives the following C + D = 42The third step is to take the values of A + B which equals 48, and C + D which equals 42 and add them together; 48 + 42 = 90I hope this explanation was of some help to you.

Ultraglide

278 Posts

 Posted - 11/13/2008 :  12:53:54 How do you know B is 24 when you substituted it into B+C+D?

Haven
Senior Member

USA
28 Posts

 Posted - 11/13/2008 :  18:04:02 I made an assumption based upon my understanding of the word "average" and the information given. If my assumption was incorrect, then I stand corrected and kindly give a better explanation.Thanks

Subhotosh Khan

USA
9114 Posts

 Posted - 11/13/2008 :  18:15:47 the correct response to the problem is - insufficient data.

the_hill1962

USA
1439 Posts

 Posted - 11/14/2008 :  12:49:44 I was thinking that "insufficient data" is the correct response.The ONLY data given is two equations:1. (A+B)/2 = 242. (B+C+D)/3 = 22This means that [3(A+B) + 2(B+C+D)]/6 = 46.That is 3A+5B+5C+2D=276, nothing more. Edited by - the_hill1962 on 11/14/2008 12:51:05

Haven
Senior Member

USA
28 Posts

 Posted - 11/14/2008 :  15:00:03 Thanks.
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