Final answer:
Ryan's combined implicit marginal tax rate, calculated by summing the reductions in food stamp and housing benefits, is 45%.
Step-by-step explanation:
The combined implicit marginal tax rate paid by Ryan is calculated by adding the reduction rates of his food stamp and housing benefits as his income increases. For every $100 Ryan earns, his food stamp benefits are reduced by $30 and housing benefits are reduced by $15. Therefore, the combined reduction amounts to $30 + $15, which is $45. Thus, for every $100 earned, Ryan effectively pays $45 in the form of reduced benefits. The combined implicit marginal tax rate is the percentage of this reduction relative to the amount earned, which would be $45 out of $100, or 45%