Final answer:
The best estimate of the total time Yolanda read on Monday and Tuesday is 3 4/5 hours, but the closest option given is 4 hours, which is an underestimate.
Step-by-step explanation:
To find the best estimate of the total time Yolanda read on Monday and Tuesday, we can add the time she read on each day. Yolanda read for 1 1/5 hours on Monday and for 2 3/5 hours on Tuesday.
To add these two fractions of an hour, we need to convert them to the same denominator. The least common multiple of 5 and 5 is 5, so we can rewrite 1 1/5 as 6/5 and 2 3/5 as 13/5.
Now we can add the fractions: 6/5 + 13/5 = 19/5.
To simplify this fraction, we divide the numerator by the denominator: 19 ÷ 5 = 3 remainder 4.
So the best estimate of the total time Yolanda read on Monday and Tuesday is 3 4/5 hours.
However, none of the given options matches this answer exactly. The closest option is 4 hours (option b), which is an underestimate of the actual time.