{ a,b,c,d } d. p { 3,5,7,9 }
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a+b+c+d = 144
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a / 3 = b / 5 = c / 7 = d / 9 = K
a / 3 = K => a = 3 K
b / 5 = K => b = 5 K
c / 7 = K => c = 7 K
d / 9 = K => d = 9 K
3 K + 5 K + 7 K + 9 K = 144
24 K = 144
K = 144 : 24
K = 6
a = 3 x 6 = 18
b = 5 x 6 = 30
c = 7 x 6 = 42
d = 9 x 6 = 54