Question 639381
Let the son's, sister's and father's age be x,y and z respectively. X=5+y---(1) x=(1/6)z 6x=z---(2) x+y+z=51---(3) from (1) y=x-5---(4) substitute (4) n (2) into (3) x+x-5+6x=51 8x=56 x=7 y=7-5=2 z=6*7=42