Question

mark wants to paint a mural. He has 1 1/3 gallons of yellow paint, 1 1/4 gallons of green paint, and 7/8 gallon of blue paint. mark plans to use 3/4 of each paint color. how many gallons of paint will he have left after painting the mural

Answer 1

Mark has:  1 1/3 = 4/3  gallons of Yellow
                 1 1/4 = 5/4  gallons of Green
                            7/8  gallons of Blue.

Total =  (4/3 + 5/4 + 7/8)    LCM = 24
        =  (32 + 30 + 21)/24 = 83/24  Gallons of Paint in total.

If he used 3/4 of each, he would have (1 - 3/4) = 1/4 of each left.

Therefore gallons left =  1/4 * (83/24) = 83/96 gallons left.
                                                     =  0. 8646 gallons left in total.

Answer 2

we have

Yellow paint

$1\frac{1}{3} =(3*1+1)/3\\ \\ =\frac{4}{3} gal$

Find the
amount of yellow paint left after painting the mural

$(\frac{4}{3} -\frac{3}{4} )=(4*4-3*3)/12\\ \\ =\frac{7}{12} gal$

Green paint

$1\frac{1}{4} =(4*1+1)/4\\ \\ =\frac{5}{4} gal$

Find the
amount of green paint left after painting the mural

$(\frac{5}{4} -\frac{3}{4} )=(5-3)/4\\ \\ =\frac{2}{4} gal$

Blue paint

$\frac{7}{8}gal$

Find the
amount of blue paint left after painting the mural

$(\frac{7}{8} -\frac{3}{4} )=(7-2*3)/8\\ \\ =\frac{1}{8} gal$

Find the
total amount of paint left after painting the mural

$\frac{7}{12} +\frac{2}{4} +\frac{1}{8} =\frac{(2*7+6*2+3*1)}{24} \\ \\ =\frac{29}{24} gal$

$\frac{29}{24} =1\frac{5}{24} gal$

therefore

the answer is

$1\frac{5}{24} gal$