3 times the sum of 1 third and 2 fourts

2.5

Step-by-step explanation:

Find a common denominator between 3, 4 and you’ll find 12. So then turn 1/3 and 2/4 into fractions that contain 12 as the denominator and you’ll get 4/12 (1/3) and 6/12 (2/4). Now that you have a common denominator, you can add. 4/12 + 6/12 = 10/12 which is simplified into 5/6. Now you’re going to cross multiply 10/12 and 3/1 (3) this will give you 2.5.