Answer:
100 minutes or 1 hr 40 minutes
Explanation:
rate = 60 pages/40 min = 3/2 pages per minute
his book is 210 pages
he read 60 pages
210 -60 = 150 pages left to read
150 pages = 3/2 pages per minute * time
divide each side by 3/2
150 / (3/2) = time
150 * 2/3 = time
100 minutes
subtract 60 minutes (60 minutes = 1 hr)
1 hr 40 minutes