A book has 850 pages. The ratio of number of pages 'with illustration' to that 'without illustration' is 4 : 1. How many pages of the book have illustration?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 680
In the ratio 4 : 1 the pages are 4 parts with illustrations and 1 part without, so the whole book is 5 parts.
The whole book, 5 parts, has 850 pages, so 1 part \(=850\div5=170\) pages
Pages with illustrations are 4 of these parts: \(4\times170=680\) (the other 170 pages have no illustration)