Tom and Sami need 9/5 + 37/3 gallons of paint for the two jobs. To find the total amount of paint they need, we need to add these two quantities. However, they need to have the same denominator to add them, so we will find a common denominator:
9/5 + 37/3 = (9/5)(3/3) + (37/3)(5/5) = 27/15 + 185/15 = 212/15
So they need 212/15 gallons of paint. To simplify this to the nearest whole number, we can divide both the numerator and denominator by their greatest common factor, which is 3:
212/15 = (212 ÷ 3) / (15 ÷ 3) = 70/5 = 14
So they should buy 14 gallon cans of paint.