Short Answer 
Each robber initially receives 37.5% of the loot when an eight-member gang splits it. After two members are killed, their share increases to 50%, resulting in a 33.33% increase in their percentage of loot received.
Step 1: Calculate Shares with Full Gang
To determine the percentage of the loot each of the three robbers receives when the entire gang of eight splits the loot equally, use the formula: (100 / 8) * 3. This calculation represents the distribution of the total loot among the robbers and results in a share of 37.5 percent for each robber.
Step 2: Determine Shares After Casualties
If two gang members are killed, the remaining gang size is reduced to six. To find the new percentage for the three robbers, apply the formula: (100 / (8 – 2)) * 3. This adjustment shows that with fewer members, the share for each becomes 50 percent as the loot is redistributed among the surviving members.
Step 3: Calculate Percent Increase in Shares
The final step is to find the percent increase of the robbers’ shares after the two members are killed. Start by finding the difference between the new share and the original share, which is 50 – 37.5 = 12.5. Then, divide the increase by the original share and multiply by 100 to get the percentage increase: (12.5 / 37.5) * 100, yielding an increase of approximately 33.33 percent.