soo i'm having trouble interpreting this question:
"Melissa is four times as old as Dan. Twenty years from now, Melissa will be twice as old as Dan then. What is Melissa's present age?"
suppose m is melissa, and d is dan
i get that m = 4d, and d remains as is.
in the second sentence, what does "Dan then" even mean here? does that mean that we won't be adding 20 there?
any help appreciated, thanks.
in 20 years:
M+20 = 2(D+20)
M+20 = 2D +40
M = 2D + 20 From the first equation 1/2M = 2D Substitute this
M=1/2M + 20
1/2M = 20
M= 40 D=10
And in 20 years
M= 60 D=30