Let's say we had 12 skateboards and 12 scooters. I'm picking 12 because 4*3 = 12 after multiplying the denominators. Doing this trick will mean we end up with whole number results instead of decimals.
If we had 12 skateboards, then (1/4)*12 = 3 of them are red. Having 12 scooters means (2/3)*12 = 8 scooters are red.
Add up the counts of each red item to get 3+8 = 11 red items out of 12+12 = 24 items total. Therefore, the answer is 11/24
Side note: The fraction 11/24 cannot be reduced because 11 and 24 have no factors in common other than 1.
