Mary, who is sixteen years old, is four times as old as her brother. How old will Mary be when she is twice as old as her brother?
M=16
M=4B
(M+t)=2(B+t)
so B= 4, then
M+t=8+2t
8=t
so mary will be 16+8=24, brother 12, now Mary is 16, brother is 4
To solve this problem, we need to set up an equation based on the information given. Let's say the age of Mary's brother is represented by x.
According to the problem, Mary is currently four times as old as her brother, so her age can be expressed as 4x.
We need to find the age at which Mary will be twice as old as her brother. Let's call this future age represented by y.
To set up the equation, we can say that when Mary is y years old, she will be twice as old as her brother, which means her brother's age will be half of that, or y/2.
Since we know that Mary is four times as old as her brother, we can set up the equation as follows:
4x + y = 2 * (y/2)
Simplifying this equation, we have:
4x + y = y
Now, we can solve for y to determine Mary's age at that point.
Subtracting y from both sides of the equation, we get:
4x = 0
Dividing both sides by 4, we find:
x = 0
It appears that there's an error in the problem since we cannot determine Mary's age when she is twice as old as her brother using the information provided.