Problema Solution
If a and b have a total of 21 books and a has twice as many as b, how many books does b have?
Answer provided by our tutors
let 'x' represent the number of books 'b' has, then '2x' represents the number of books 'b' has:
21 = x + 2x
x = 21/3 = 7
2*7 = 14
a has 14 books, b has 7 books