The investment ratio for the first six months is given as 3 : 4 : 5. After six months, each partner increases their investment by 10%, 15%, and 20%, respectively. We need to calculate the total investment for each partner over the entire year and find the ratio of their shares in the total profit.
Step 1: Calculate the total investment for the first six months.
Let the initial investments for the three partners be \( 3x \), \( 4x \), and \( 5x \) for the first six months.
Step 2: Calculate the increased investment for the next six months.
The new investments are calculated as follows:
- Partner 1: \( 3x \times 1.1 = 3.3x \)
- Partner 2: \( 4x \times 1.15 = 4.6x \)
- Partner 3: \( 5x \times 1.2 = 6x \)
Step 3: Calculate the total investment for the year.
- Partner 1: Total investment \( = 3x \times 6 + 3.3x \times 6 = 18x + 19.8x = 37.8x \)
- Partner 2: Total investment \( = 4x \times 6 + 4.6x \times 6 = 24x + 27.6x = 51.6x \)
- Partner 3: Total investment \( = 5x \times 6 + 6x \times 6 = 30x + 36x = 66x \)
Step 4: Find the ratio of the total investments.
The ratio of their total investments is \( 37.8x : 51.6x : 66x \). Simplifying the ratio, we get:
\[ 37.8 : 51.6 : 66 = 63 : 86 : 110 \]
Thus, the correct ratio of their shares in the total profit is \( 63 : 86 : 110 \).