That means,Originally Posted byadriano1028

15 Employees|6 hours|9 days.

Thus, 1 Employee need to work for 90 hours a day, Thus,

1 Employee|90 hours|9 days.

Thus, working for 1 hour he needs 9x90=810 days, Thus,

1 Employee|1 hour| 810 days.

This to do the same amount of work, 1 employee working for 1 hour needs 810 days.

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We need to find

X Employees|9 hours|5 days

Thus, 1 Employee needs to work for 9X hours a day, Thus,

1 Employee|9X hours|5 days

Thus, working for 1 hours he needs 45X hours a day, Thus,

1 Employee|1 hour|45X days.

This to do the same amount of work, 1 employee working for 1 hour needs 45X days.

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Before we show it is 810 days, thus,

45X=810 days,

Thus,

X=18 Employees.