Family and age ratios

Age of father and son are in the ratio 10:3; age of father and daughter are in the ratio 5:2. How old is father and son, if daughter is 20 years old? In what ratio is age sister and brother?


d =  20
o =  50
s =  15
x =  4:3


3o = 10s
2o = 5d
d = 20

3o-10s = 0
5d-2o = 0
d = 20

d = 20
o = 50
s = 15

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Solution in text x =

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