Began by dividing 850 by 1, then 2, then 3, and so on, and I made a list of the whole numbers.
They were 1, 2, 5, 10, 17, 25, 34, 50, 85, 170, 425, and 850
By inspection, the two smallest numbers which when multiplied together yielded 850 were 25 and 34.
Answer:
20 miles
Step-by-step explanation:
d miles × (1 h)/(10 miles) = d/10 hours
d miles × (1 h)/(40 miles) = d/40 hours
d/40 = d/10 - 3/2
d = 4d - 60
d = 20 miles
