# Abag contains green marbles and blue marbles, 16 in total. The number of green marbles is 8 less than 2 times the number of blue marbles, How many green marbles are there?

##### 1 Answer
Dec 10, 2016

Assign a variable for the number of blue marbles.

#### Explanation:

In this case, let's use y.

To find the number of green marbles, assign an expression following information from the question, which gives you;

$\left(2 y - 8\right) + y = 16$

Here, the expression $2 y - 8$ will give you the total number of green marbles, hence you can just solve the equation;

$3 y - 8 = 16$
$16 + 8 = 3 y$
$24 = 3 y$
$y = 8$

There are 8 blue and 8 green marbles.

Substitute 8 for y to find the green marbles;

$2 \left(8\right) - 8 = 8$