Please help me to solve this. I have solution but do not know how to solve.

Use the the marginal tax information in the table below to calculate the after tax monthly income Kelly should expect from her retirement income. Kelly expects $13,775 annually from CPP, $7,907 annually from OAS, and $118,000 from her RRIF. Assume that her OAS will be clawed back on any income above $76,000.

Simplified Marginal Tax Table
Beginning of range		End of range	Tax at start of range	Marginal rate
-	to	12,000	-	0%
12,000	to	20,000	-	15%
20,000	to	48,000	1,200	22%
48,000	to	95,000	7,360	30%
95,000	to	148,000	21,460	40%
148,000	to	210,000	42,660	45%
210,000	+	above	70,560	50%

Correct Answer:

7,967 1