This is a word problem dealing with percentages of Jan's monthly income. Choose $100 for Jan's total monthly income. If she spent 40% of that on her housing, that means she spent $40 on her housing. She spent 20% less than $40 on her car payment. 20% of $40 is (0.20)($40) = $8, so she spent $40 - $8, or $32 on her car payment. The total amount spent for housing and car was 40 + 32, or $72, which subtracted from $100, leaves her with $28. $28 is 28% of her monthly income. (B) is correct.