machine can make 48 shirts in 4 hours how many hours it will take to make 840 shirts

ANSWER-   no.of shirts made by a machine in 4 hours= 48
                    no.of shirts made in 1 hour= 48 divided by 4 = 12
                    therefore hours taken by the machine to make 840 shirts = 840 divided by 12 = 70 hours

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