Help me with this pls!!

5 3/4 hours

Step-by-step explanation:

They drove 3 1/2 hours then  2 1/4 hours. We need to find the total of these to find how long this part of the trip was

(3 + 1/2) + (2 + 1/4) = 5 + 1/2 + 1/4

For 1/2, we can multiply both the numerator and denominator by 2 to get

1/2 = 2/4

Substituting that in, we get

5 + 2/4 + 1/4

= 5 + 3/4 hours