A cup contains green and red marbles. If there are 18 marbles in the cup, which of the following could NOT be the ratio of green to red marbles? 2:3 1:2 1:1 1:5 1:8

Marbles can not be in the ratio of 2:3.

Step-by-step explanation:

In this question total number of marbles are = 18

Ratio of green: Red marbles are 2:3 1:2 1:1 1:5 1:8

1). First we take the ratio of 2:3

Then number of green marbles = 18 * (2/5) = 36/5

and number of red marbles = 18 * (3/5) = 54/5

Which is not possible because number of marbles can not be in fraction.

2). In ratio of 1:2

Number of green marbles = 18 * (1/3) = 6

Number of red marbles = 18 * (2/3) = 12

3). In the ratio of 1:1

Red and green are equal = 9 marbles each

4). In the ration of 1:5

Green marbles = 18 * (1/6) = 3

Red Marbles = 18 * (5/6) = 15

5). In the ration of 1:8

Green marbles = 18 * (1/9) = 2

Red marbles = 18 * (8/9) = 16