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There are three brothers. Two of them are twins.The age of one brother is cube of the other. Next year the age of one brother would be square of the other. What is the sum of their current ages?

 Jun 27, 2020
 #1
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By just looking at it:

2    and   8         in one year they will be     3   and   9      trying to find a mathematical solution.....

 

x = y^3    and

x+1 = (y+1)^2

 x+1 = y^2+2y+1

x = y^2+2y

y^3 = y^2 + 2y

y^3 - y^2-2y=0

y(y^2-y-2)=0

y(y-2)(y+1) = 0     y = 2   0 (throw out)  -1 (throw out)   

 

so y = 2   x = 8 

 Jun 27, 2020
edited by ElectricPavlov  Jun 27, 2020

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