when rounding up, decimals tend to lose accuracy, thus the rounding, due to that, fractions will always be the most accurate to represent the value, but let's go ahead
3/5 = 0.6 <- rounded up to one decimal
3/4 = 0.75
= 0.8 <- rouned up to one decimal as well
if we add them up 0.6 + 0.8 = 1.4.
in this case, rounding up each result to 1 decimal, we end up with the same value, mind you that the instructions never said to round it to a certain amount of decimal places, if we do round it to two decimal places, the value will be 1.35 for both cases, and accurate on each.