Answer: $165
Step-by-step explanation:
It appears that the interest rate is simple interest, that is calculated at the end of each year.
if that is the case, then Mark will receive an interest payment of $5000 x 2.1 = $105
Charles will receive an interest payment of $5000x 0.054 = $270
so, Charles will receive $270 - 105 = $165 more than Mark