Three partners Ramesh, Suresh and Mahesh shared the profit in a business in the ratio 5 : 4 : 7 respectively, they invested the money for 10 months, 8 months and 6 months respectively then ratio of their investment is :

3 : 3 : 7

Profit ratio $=5:4:7$

Time of investment

Ramesh $=10$ months

Suresh $=8$ months

Mahesh $=6$ months

Profit ratio $\propto$ Investment $\times$ Time

Let investments be $R,S,M$

$R\times10 : S\times8 : M\times6 = 5:4:7$

$R:S:M = \frac{5}{10} : \frac{4}{8} : \frac{7}{6}$

$= \frac{1}{2} : \frac{1}{2} : \frac{7}{6}$

Multiply by $6$

$=3:3:7$

The ratio of their investments is $3:3:7$.