Question

Katrina is building a deck. She cuts 3 lengths of wood from a 72-inch board. The first length is 30 3/4 inches. The second length is 12 1/4 inches. And the third length is 16 1/4 inches. How much of the original board remains after Katrina makes her cuts? help me pleaz !!!!!!!!

Answer 1

first add them together
30 and 3/4+12 and 1/4+ 16 and 1/4=30+3/4+12+1/4+16+1/4 =30+12+16+3/4+1/4+1/4=58+1+1/4=59+1/4=59 and 1/4
subtract from 72
72-59 and 1/4=72-(59+1/4)=72-59-1/4=71+1-59-1/4= 71-59+1-1/4= 71-59+4/4-1/4=12+3/4

the legnth left is 12 and 3/4 inches

Answer 2

Let

x-------> remainder of the original board

we know that

`72=30(3)/(4) +12(1)/(4)+16(1)/(4) +x` ------> equation
`1`

Convert mixed numbers to an improper fractions

`30(3)/(4)=(30*4+3)/(4)=(123)/(4)`

`12(1)/(4)=(12*4+1)/(4)=(49)/(4)`

`16(1)/(4)=(16*4+1)/(4)=(65)/(4)`

Substitute the values in the equation
`1` and solve for x

`72=(123)/(4) +(49)/(4)+(65)/(4) +x`

`72=(237)/(4) +x`

solve for x

`x=72-(237)/(4)`

`x=72-59.25`

`x=12.75\ inches`

convert to mixed number

`x=12.75\ inches=12+0.75=12+(3)/(4)=12(3)/(4)\ inches`

therefore

the answer is

`12(3)/(4)\ inches`