Each morning Boris walks to school. At one-fourth of the way he passes the machine and tractor station; at one-third of the way, the railroad station. At the machine and tractor station its clock shows 7:30, and at the railroad station its clock shows 7:35.
When does Boris leave his house, when does he reach school?
Answer
He leaves his house at 7.15 and reaches school at 8.15.
From the machine and tractor station to the railroad station is 1/3 – 1/4 = 1/12 of the way. Boris walks it in 5 minutes, so the whole trip takes 1 hour.
One-fourth of the way is 15 minutes. So he leaves his house at 7:15 and reaches school at 8:15.