To answer this, you can use the pictures of the fraction strips that I have attached.
You will need 1 group of 1/4, 2 groups of 1/8 to make 2/8, and three groups of 1/12 to make 3/12.
The 2/8 equals 1/4.
The 3/12 also equals 1/4.
Altogether you have 3 groups of 1/4 which is 3/4.
The students painted 3/4 of the mural.
