To determine if 3.5 liters of glue will be enough, you can set up a proportion using the ratio of glue to water (3:1).
<u>3 L glue </u> <u>3.5 L glue</u>
1 L water = x L water
Use cross products to solve for the amount of water.
<u>3x</u> = <u>3.5</u>
3 3
x = 1.17 L
You will need approximately 1.17 L of water with 3.5 L of glue. This is a total of 4.67 L, which is NOT enough.
You will <u>not</u> be able to make the mixture.
we have
------> inequality A
The solution of the inequality A is the shaded area below the dotted line
see the attached figure N 
------> inequality B
The solution of the inequality A is the shaded area above the dotted line
see the attached figure N
The solution of the system of linear inequalities is the shaded area between the two dotted lines
see the attached figure N 
therefore
the answer in the attached figure N 

divide the numerator and denominator by 13
=
To evaluate the data set shown we need to rearrange the sets from smallest to the largest
5,7,10,10,12,12,12,13,15,17,18,18,18,19,20,20
thus the:
first quarter, Q1 will be:
(10+7)/2
17/2
=8.5
second, Median
(13+15)/2
=28/2
=14
Third quarter, Q3:
(19+20)/2
=39/2
=19.5
Thus you can use the values obtained to mark the number line.