Question

A java book is comprised of two sections core and advanced java in the ratio 7:2. How much of each type of content will be needed to make a book of 450 pages? answer

Answer 1

Let core java section requires = 7x pages
Advanced java section requires = 2x pages

Total pages = 7x +2x = 9x 
But but total pages = 450
Thus 9x = 450
or x=50

So core java section requires = 7x = 7X50 = 350 pages
Advanced java section requires = 2x = 2X50 = 100 pages

Answer 2

Let
core java section pages = 7x pages
Advanced java section pages = 2x pages
total java book pages=>450=(7x+2x)pages
                              =>9x=450
                              =>x=450/9
                              =>x=50
core java pages=>7x=7*50=350 pages
advanced java pages=>2x=2*50=100 pages