Mary logged into work at 8:10 am and logged out at 3:45 pm. How many hours did she work? (Her employer rounds to the nearest quarter hour.)

1.8

2.7 1/2

3.7 3/4

4.8 1/4

I'm assuming your answers are listed as 1 through 4, not decimals.

You simply take 12 - 8 = 4, but ten min. less than that, so 3 hr, 50 min. then add 3 hr 45 min, totaling 7 hr 35 min., which is closest to 7 and 1/2 hours, the second option.