Question

Gary bought a pen a book and a calculator. The book cost 2 times as much as the pen and the calculator cost $1 more than the book.He spent $16 altogether.What was the cost of the book?

Answer 1

A few things you're given:

b=book

p=pen

c=calculator

b + p + c = 16

Relationships in order to only use one variable:

2p=b

2p+1=c

Equation:

2p + p + 2p+1 = 16

Combining Like Terms/Simplifying and Solving:

5p + 1 = 16

5p = 15

p = 3

Remember the relationship between pen and book.

2p = b so...

2 (3) = $6.00! :)