John had a stock of 800 books in his bookshop. He sold 62 on Monday, 62 on Tuesday, 60 on Wednesday, 48 on Thursday and 40 on Friday. What percentage of the books were not sold?  Answers
A) 26.5%  B) 36.5%  C) 71.7%  D) 56.5%  E) 70.0%
Let N be the total number of books sold. Hence   N = 75 + 50 + 64 + 78 + 135 = 272   Let M be the books NOT sold   M = 960 - N = 960 - 402 = 688   Percentage   Books not sold / total number of books = 688/960= 0.72 = 71.7%   correct answer 71.7%
<result>C</result>
John had a stock of 800 books in his bookshop. He sold 62 on Monday, 62 on Tuesday, 60 on Wednesday, 48 on Thursday and 40 on Friday. What percentage of the books were not sold?