Well 40 times 6 is 240 which means that you don't have to round.
First you would make the mixed fractions into improper fraction by multiplying the denominator and the whole number, then adding the numerator. Then you would flip the second fraction and multiply.
Ex. 1 1/2 ÷1 1/2
1st. 3/2÷3/2
2nd: 3/2×2/3
3rd 3/2x2/3=1
The answer to this is C.54 units² .
Area=1/2 base*height
base=12
height=9
12*9=108
108/2=54
Area=54
