Question

A factory has 80 workers and 3 machines. Each worker knows to operate atleast 1 machine. If there are 65 persons who knows to operate machine 1, 60 who knows to operate machine 2 and 55 who knows to operate machine 3,what can be the minimum number of persons who knows to operate all the three machines?
15
20
30
40

Answer 1

this type is answer fifteen

Answer 2

Answer:

20

Step-by-step explanation:

80-[(80-65)+(80-60)+(80-55)]

= 80 - 60 = 20