testing header
Math Goodies is a free math help portal for students, teachers, and parents.
Free Math
Newsletter
 
 
Interactive Math Goodies Software

Buy Math Goodies Software
testing left nav
Math Forums @ Math Goodies
Math Forums @ Math Goodies
Home | Profile | Register | Active Topics | Members | Search | FAQ
Username:
Password:
Save Password
Forgot your Password?

 All Forums
 Homework Help Forums
 Standardized Test Preparation Help
 help me average problem
 New Topic  Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  

sri340
Average Member

USA
18 Posts

Posted - 11/13/2008 :  07:41:13  Show Profile  Reply with Quote
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
Go to Top of Page

Haven
Senior Member

USA
28 Posts

Posted - 11/13/2008 :  11:37:28  Show Profile  Reply with Quote
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 = 42

The 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 = 90

I hope this explanation was of some help to you.



Go to Top of Page

Ultraglide
Advanced Member

Canada
299 Posts

Posted - 11/13/2008 :  12:53:54  Show Profile  Reply with Quote
How do you know B is 24 when you substituted it into B+C+D?
Go to Top of Page

Haven
Senior Member

USA
28 Posts

Posted - 11/13/2008 :  18:04:02  Show Profile  Reply with Quote
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
Go to Top of Page

Subhotosh Khan
Advanced Member

USA
9117 Posts

Posted - 11/13/2008 :  18:15:47  Show Profile  Reply with Quote
the correct response to the problem is - insufficient data.
Go to Top of Page

the_hill1962
Advanced Member

USA
1468 Posts

Posted - 11/14/2008 :  12:49:44  Show Profile  Reply with Quote
I was thinking that "insufficient data" is the correct response.
The ONLY data given is two equations:
1. (A+B)/2 = 24
2. (B+C+D)/3 = 22
This 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
Go to Top of Page

Haven
Senior Member

USA
28 Posts

Posted - 11/14/2008 :  15:00:03  Show Profile  Reply with Quote
Thanks.
Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
Math Forums @ Math Goodies © 2000-2004 Snitz Communications Go To Top Of Page
This page was generated in 0.06 seconds. Snitz Forums 2000
testing footer
About Us | Contact Us | Advertise with Us | Facebook | Blog | Recommend This Page




Copyright © 1998-2014 Mrs. Glosser's Math Goodies. All Rights Reserved.

A Hotchalk/Glam Partner Site - Last Modified 21 May 2014