A school store has 1200 pencils in stock and sells an average of 24 pencils per day the manager reorders when the number of pencils in stock is 500. in how many days will the manager have to reorder

Number of pencils in stock = 1200
Average number of pencils sold by the manager per day = 24
Number of pencils that would be sold before reordering = 1200 - 500
                                                                                         = 700
The number of days after which the manager will reorder = 700/24
                                                                                             = 29.16
So the manager has to reorder after about 30 days. Since the answer comes in fraction of more than 29 days, so it has to be 30 days. I hope the procedure is clear for your understanding.