SOLUTION: the combined age of 2 brothers is 35 years old.7 years ago one brother was twice the age of the other. how many years apart were they born
Algebra.Com
Question 1204081: the combined age of 2 brothers is 35 years old.7 years ago one brother was twice the age of the other. how many years apart were they born
Found 3 solutions by mananth, greenestamps, josgarithmetic:
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
the combined age of 2 brothers is 35 years
let the brother's ages be x & y
x+y=35.................................................(1)
7 years ago one brother was twice the age of the other.
7 years ago
One brother was x-7 years
The other was y-7 years
x-7 = 2(y-7)
x-7 =2y-14
x-2y = -7............................................(2)
subtract (2) from (1)
x+y=35
x-2y = -7
3y =42
y = 14
x+y =35
x+14=35
x= 21
Since we know their present ages we can find how many years apart were they born
Answer by greenestamps(13200) (Show Source): You can put this solution on YOUR website!
The solution from tutor @mananth is a very inefficient solution using two variables, starting from the given information that the sum of their current ages is 35 years.
"7 years ago one brother was twice the age of the other" gives us a much easier way to set up the problem for solving, using a single variable.
Let x = age of younger brother 7 years ago
then 2x = age of older brother 7 years ago
The difference in their ages at any time is the difference in their ages 7 years ago, which is 2x-x = x.
The sum of their current ages is 35:
(x+7)+(2x+7)=35
3x+14=35
3x=21
x=7
ANSWER: the difference in their ages is 7 years -- i.e., they were born 7 years apart
Answer by josgarithmetic(39617) (Show Source): You can put this solution on YOUR website!
OR maybe this way:
v and 35-v
and
Those two ages differ by 7 years.
RELATED QUESTIONS
The combined age of two brothers is 35 years. Seven years ago, one brother was twice the... (answered by josgarithmetic,MathTherapy)
A man and his brother have a combined age of 164 years. 46 years ago, the man was 7 times (answered by scott8148)
A man and his brother have a combined age of 164 years. 46 years ago, the man was 7 times (answered by scott8148,Fombitz)
Exactly one year ago, Robert was twice the age of his younger brother John. Now, John is... (answered by Alan3354)
fred is 2 years older than his brother. 12 years ago fred was twice his brothers age how (answered by Alan3354,MathLover1)
If a person is twice as old as his brother. 3 years ago the sum of their ages was 27.... (answered by algebrahouse.com)
10 times my age minus 5 times my brothers age is 100. 10 years ago the square of my age... (answered by ankor@dixie-net.com)
A man and his brother have a combined age of 162 years. 49 years ago, the man was 7 times (answered by edjones)
Five years ago Jacob was one-sixth the age of his brother. Three years time his age... (answered by htmentor)