How does the path of water at the bottom of the can change as the water level in the can falls

Given:
annual salary: 56,010
social security tax rate: 6.2%
medicare tax rate: 1.45%

both these taxes are computed based on the annual salary.

social security tax:
56,010 x 6.2% = 3,472.62

medicare tax:
56,010 x 1.45% = 812.145 or 812.15

total taxes paid:
3,472.62 + 812.15 = 4,284.77

The answer is b. social security tax: $3,472.62, medicare tax: $812.15