GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 18 Oct 2019, 20:20

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# The average weight of 3 men A, B and C is 84 kg. Another man D joins t

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 58453
The average of weight of three men A,B and C is 84 kg. Another man D j  [#permalink]

### Show Tags

21 Feb 2019, 00:53
00:00

Difficulty:

45% (medium)

Question Stats:

73% (03:17) correct 27% (02:56) wrong based on 41 sessions

### HideShow timer Statistics

The average of weight of three men A,B and C is 84 kg. Another man D joins the group and the average now becomes 80 kg. If another man E, whose weight is 3 kg.more than that of D, replaces A, then the average weight of B,C,D and E becomes 79 kg. The weight of A is :

A. 70 kg
B. 72 kg
C. 75 kg
D. 80 kg
E. 82 kg

_________________
VP
Joined: 31 Oct 2013
Posts: 1464
Concentration: Accounting, Finance
GPA: 3.68
WE: Analyst (Accounting)
The average of weight of three men A,B and C is 84 kg. Another man D j  [#permalink]

### Show Tags

21 Feb 2019, 03:46
Bunuel wrote:
The average of weight of three men A,B and C is 84 kg. Another man D joins the group and the average now becomes 80 kg. If another man E, whose weight is 3 kg.more than that of D, replaces A, then the average weight of B,C,D and E becomes 79 kg. The weight of A is :

A. 70 kg
B. 72 kg
C. 75 kg
D. 80 kg
E. 82 kg

A + B + C = 84 * 3 = 252

A + B + C + D = 80 * 4 = 320

D = (A + B + C + D) - ( A + B + C) = 320 - 252 = 68.

E = D + 3 = 68 + 3 = 71.

B + C + D + E = 316.

B + C + D + 71 = 316.

B + C + D = 245.

We know,

A + B + C + D = 320

A + 245 = 320

A = 75.

Manager
Joined: 13 Oct 2018
Posts: 85
Location: India
GPA: 3.1
WE: Information Technology (Computer Software)
Re: The average weight of 3 men A, B and C is 84 kg. Another man D joins t  [#permalink]

### Show Tags

21 Feb 2019, 08:10
1
If E = F ( due to a typo )

we have

1. A+B+C = 84*3 = 252

2. A+B+C+D = 80*4 = 320

After A's replacement , new E = D+3

3. B+C+D+D+3 = 79*4

from 1 and 2 , D = 320 -252 = 68

from 3, B+D = 316 - (2*68+3)
= 177

So from 1 ,

A = 252 -177 = 75 Option C
_________________
Ankit
GMAT is tough so I am ...
Giving Kudos is the best way to encourage and appreciate people
GMAT Club Legend
Joined: 18 Aug 2017
Posts: 5020
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
Re: The average of weight of three men A,B and C is 84 kg. Another man D j  [#permalink]

### Show Tags

21 Feb 2019, 10:28
Bunuel wrote:
The average of weight of three men A,B and C is 84 kg. Another man D joins the group and the average now becomes 80 kg. If another man E, whose weight is 3 kg.more than that of D, replaces A, then the average weight of B,C,D and E becomes 79 kg. The weight of A is :

A. 70 kg
B. 72 kg
C. 75 kg
D. 80 kg
E. 82 kg

a+b+c= 252
and
d= 320-252 ; 68
e= 71
so
b+c= 252-a
so
252-a+68+71 = 79*4
a= 75
IMO C
GMAT Club Legend
Joined: 18 Aug 2017
Posts: 5020
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
Re: The average weight of 3 men A, B and C is 84 kg. Another man D joins t  [#permalink]

### Show Tags

21 Feb 2019, 10:48
Bunuel wrote:
The average weight of 3 men A, B and C is 84 kg. Another man D joins the group and the average now becomes 80 kg. If another man F, whose weight is 3 kg more than that of D, replaces A then the average weight of B, C, D and E becomes 79 kg. The weight of A is:

A. 70
B. 72
C. 75
D. 79
D. 80

a+b+c=252
b+c= 252-a

now
a+b+c+d= 320
d = 68 kg and f = 71
so
252-a+68+71= 79*4
a = 75
IMO C
Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8109
Location: United States (CA)
Re: The average weight of 3 men A, B and C is 84 kg. Another man D joins t  [#permalink]

### Show Tags

24 Feb 2019, 06:52
Bunuel wrote:
The average weight of 3 men A, B and C is 84 kg. Another man D joins the group and the average now becomes 80 kg. If another man F, whose weight is 3 kg more than that of D, replaces A then the average weight of B, C, D and E becomes 79 kg. The weight of A is:

A. 70
B. 72
C. 75
D. 79
D. 80

We can create the equation:

(A + B + C)/3 = 84

A + B + C = 252

We also have:

(A + B + C + D)/4 = 80

(252 + D)/4 = 80

252 + D = 320

D = 68, and E = 68 + 3 = 71

Now we can create the equation:

(B + C + D + E)/4 = 79

B + C + 68 + 71 = 316

B + C + 139 = 316

B + C = 177

Since A + B + C = 252, subtract B + C = 177 from it, obtaining:

A = 252 - 177 = 75

_________________

# Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

Director
Joined: 27 May 2012
Posts: 902
Re: The average weight of 3 men A, B and C is 84 kg. Another man D joins t  [#permalink]

### Show Tags

17 Mar 2019, 07:11
Bunuel wrote:
The average weight of 3 men A, B and C is 84 kg. Another man D joins the group and the average now becomes 80 kg. If another man F, whose weight is 3 kg more than that of D, replaces A then the average weight of B, C, D and E becomes 79 kg. The weight of A is:

A. 70
B. 72
C. 75
D. 79
D. 80

Although the answer is 75, addition of variable E is causing some confusion.I guess the last line means B C D and F.
So we have A+B+C=252
A+B+C+D=320 So D=68
Now F =71
Now we have 71+B+C+68=316 so B+C=177
A+177+68=320
so A = 320 -245 =75

P.S. Variable E seems to be in error.
_________________
- Stne
Re: The average weight of 3 men A, B and C is 84 kg. Another man D joins t   [#permalink] 17 Mar 2019, 07:11
Display posts from previous: Sort by