Daryl makes $2,750.00 every month. If he is required to put 4% into his companies retirement account, how much will he pay into his retirement account for the month?

Question and answers are in the attached picture. you so much in advance.

Can someone me with this problem i don't understand i need

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )