B. 20 : 49 : 64
Feedback Let their investments be Rs. x for 14 months, Rs. y for 8 months and Rs. z for 7 months respectively. Then, 14x : 8y : 7z = 5 : 7 : 8.
Now,14x/8y=5/7
=> 98x = 40y
=> y =49/20x.
And,14x/7z=5/8
=> 112x = 35z
=> z = 112/35x = 16/5x
=> x : y : z = x :49/20x:16/5x= 20 : 49 : 64.