Makoto's lacrosse practice last 1 3/4 hours. this week he attended all of the practice on monday and wednesday, but he had to leave halfway through practice on friday. how many hours did makoto's spend at lacrosse practice this week?

For this case we must know the number of hours per day.
 We have then:
 Monday = 1 3/4 hours
 Wednesday = 1 3/4 hours
 Friday = (1 3/4) / (2) hours
 Adding we have:
 1 3/4 + 1 3/4 + (1 3/4) / (2)
 Rewriting:
 1.75 + 1.75 + 1.75 / 2
 1.75 (1 + 1 + 1/2)
 1.75 (2 + 1/2)
 1.75 * (5/2)
 4.375
 = 4 + 0.375
 = 4 + 375/1000
 = 4 + 15/40
 = 4 + 3/8
 = 4 3/8
 
 Makoto's spend at lacrosse practice this week about:
 4 3/8 hours