Andrew's father buys a package of 100 masks. Andrew lives with his 2 parents and 2 siblings. All members of Andrew's family change masks every 4 days. How many days will it take to finish the pack of masks?
Andrew's family consists of 1 + 2 + 2 = 
<gadget id="calculator">1+2+2</gadget>
<output>5</output>
5 people.
Each of Andrew's family members uses 100 masks / 5 = 
<gadget id="calculator">100/5</gadget>
<output>20</output>
20 masks.
With everyone wearing a mask every 4 days, the masks will last 20 masks * 4 days/mask = 
<gadget id="calculator">20*4</gadget>
<output>80</output>
80 days.

<result>80</result>