a mother is 21 years older than her new born daughter.how old will the daughter be when her age is 1/4 that of her mothers
m = d + 21
in n years,
d+n = 1/4(m+n)
4d + 4n = d+21 + n
3d + 3n = 21
d + n = 7
There are several solutions for their current ages, but they all show that the daughter is 7 when her mother is 28.
(d,m) = (1,21) + 6 = (7,28)
(d,m) = (2,23) + 5 = (7,28)
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