A patient was given four pills which he is required to take one after every forty minutes.
How long can the pills run for him? Choices:
A) 1 hour and 10 minutes.
B) 1 hour and 15 minutes.
C) 1 hour and 20 minutes.
D) 1 hour and 30 minutes.
E) 1 hour and 40 minutes.
He took the first pill at the zero minute.   He took the second pill after 20 minutes = 0+40= 
<gadget id="calculator">0+40</gadget>
<output>40</output>
40   He took the third pill after 20 minutes= 40+40= 
<gadget id="calculator">40+40</gadget>
<output>80</output>
80   He took the fourth pill after 20 minutes= 80+40=100   Then it will last for 100 minutes or an hour and 40 minutes.   Answer 1 hour and 40 minutes.
<result>E</result>
A patient was given four pills which he is required to take one after every forty minutes.
How long can the pills run for him?