This is the solution to a algebra age word problem as asked by a anonymous user: "Nona is one-third as old as her mother. Five years ago, she was only one-fifth of the age of her mother. How old is Nona now? "
It is easier to set this up with two unknowns say x and y and have 2 equations.
The 1st equation would be: x = 1/3(y) or x = y/3 since Nona is currently 1/3 as old as her mother. Now 5 years ago she was only 1/5th the mothers age so the other equation would be..
x -5 = 1/5(y - 5) multiply by 5..
5x - 25 = y - 5 so
y = 5x - 20 .. plug this back into the 1st equation and you get..
x = (5x - 20)/3 - -multiply by 3
3x = 5x - 20 so 2x = 20 and x = 10
So Nona is 10 years old currently and the mom is 30. To check this go 5 years back... Nona would be 5 and the mother would be 25 ------ 5/25 = 1/5ths of her mothers age...
Sunday, October 9, 2011
Age Problem 7 Solution
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