3/4 of 1/2 is 3/4*1/2=3/8hr. Time remaining is 1/2-3/8=4/8-1/8=1/8 (answer A). Another way of doing this is to work in minutes. 30 minutes=1/2 hr, so 3/4*30=45/2=22.5 or 22 1/2 mins. That leaves 7.5 or 7 1/2 mins. 8*7.5=60 mins=1 hr, so 7 1/2 mins is 1/8hr.