One robot builds a robot in 1 hour, another one builds a robot in 2 hours.
One robot builds a robot in 1 hour, another one builds a robot in 2 hours. The 2 robots work together and when a new robot is complete, it joins the others, working at a constant rate of one robot in 2 hours. How much time will it take until there are 3 robots altogether, if the robots build only one robot at a time?
Answer/Solution
40 min
Steps/Work
First the 2 robots work at the rate of
1 + 1/2 = 3/2
so they complete one robot in 2/3 rd of an hour = 40 minutes - (1)
And now we have 3 robots in 40 minutes
Answer -A
1 + 1/2 = 3/2
so they complete one robot in 2/3 rd of an hour = 40 minutes - (1)
And now we have 3 robots in 40 minutes
Answer -A