A pharmacy is buying enough tubs for them to make their prescriptions this week. They already have 20 tubs left in storage but they need a total of 100 tubs for the week. Of the tubs they still need to buy, they buy a quarter from a new vendor then decide to go to their usual vendor for the rest. How many tubs is the pharmacy going to buy from the usual vendor? Think carefully first, then make a decision:
They already have 20 tubs in storage, so they only need to buy 100 needed tubs - 20 tubs in storage = 80 tubs. From the new vendor, they buy 80 tubs / 4 = 20 tubs. They now have a total of 20 + 20 = 40 tubs. They are therefore going to buy 100 needed tubs - 40 owned tubs = 60 tubs from the usual vendor. So, the answer is 60.