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A # 1
The average weight of three men A, B, and C is 84 kg. A fourth man D joins them and the average weight of the four becomes 80 kg. If E whose weight is 3 kg more than D replaces A, then the average weight of B, C, D, and E becomes 79 kg. Find the weight of A.
It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.
Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.
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The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
-Bertrand Russell
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It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.
Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.
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Not sure but
A+B+c=252 ( average of 84*3) eq1
A+b+c+d=320 eq2
eq1 -eq2
d=68
b+c+d+e=316 eq3
e=d+3
sub into eq3
b+c+2d+3=316 eq4
eq2-eq4
A-d-3=4
a=d+7
(knowing d is 68)
a=75
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Well done, thinkdesigns!
It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.
Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.
Online
A # 2
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The weight of person A is 72.
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Hi keveenjones;
Welcome to the forum!
You get 3 equations in 4 unknowns:
Clear out fractions:
Subtract 1 from 2 and you get:
D = 68. Now use that in 2 and 3:
Subtract 2 from 1
A = 75.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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There are many different types of equation for find the average. I give the easy equation are given the below.
y = f^{-1}\left(\frac{f(x_1)+f(x_2)+\cdots+f(x_n)}{n}\right),
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Hi jonnyj99,
The posts are understood better with LaTeX.
It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.
Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.
Online
Hi jonnyj99;
Welcome to the forum!
Ganesh is right. You forgot the math tags on both ends of your latex.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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[hide=A's weight]85kg[hide/]
Maths!......
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Hi G-man;
That is close but the answer is 75, please see post #9.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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