Mike had 228 dollars to spend on 7 books. After buying them he had 18 dollars. How much did each book cost ?

$30

Step-by-step explanation:

We know that the cost of all of the books was 228 - 18 = 210 dollars because Mike had 18 dollars left over. Assuming that each book cost the same amount, we know that each book costs 210 / 7 = $30.

$30

Step-by-step explanation:

Total amount Mike had = $228

Amount remaining = $ 18

Amount spent on books = 228 - 18 = $210

Cost of wach book = 210/7 = $30

Cost of each book is 30 dollars.

the complete question is
Julia owes her dad $12. She wants a new blouse that just went on sale, so she borrows $20 from her sister. She pays her father $5 and spends the rest on the blouse. Which statement is true?
A. Julia’s money status is $8 because she started at –$12 and borrowed $20.
B. Julia’s money status is –$7 because she started at –$12, got $20, but only paid $5 of her debt.
C. Julia’s money status is –$27 because she started at –$12, borrowed $20, but paid off $5.
D. Julia’s money status is –$32 because she began at –$12 and borrowed $20.

we know that
Julia owes her dad $12 already and again she borrowed $20 from her sister
So,
total debt = $12+$20=$ 32.
And,
she paid $5 only to her father.
So,
Her money status is
 -32+5 = -$27 

the answer is the option 
C. Julia’s money status is –$27 because she started at –$12, borrowed $20, but paid off $5.