Glen is having his big family over for Christmas. Out of 25 people coming, 40 percent are lactose intolerant and 72% are vegetarians. Glen wants to prepare the good in advance. Can you calculate how many of the guests are both vegetarians and lactose intolerant?  Pick
A) 1	B) 2	C) 3	D) 4	E) 5
The total number of guests coming over for Christmas is n=25.   The number of lactose intolerant guests is 40% of it, thus   n (A)=40/100×25=40/4= 
<gadget id="calculator">40/4</gadget>
<output>10</output>
10.   The number of guests who are vegetarians is 72%, thus   n (B)=72/100×25=72/4= 
<gadget id="calculator">72/4</gadget>
<output>18</output>
18.   In order to calculate the number of guests who are both lactose intolerant and vegetarians we can use the following equation:   n (AnB)=n (A)+n (B) -n =10+18-25=28-25= 
<gadget id="calculator">28-25</gadget>
<output>3</output>
3.   So, 3 of Glen's guests are both lactose intolerant and vegetarians.   ANSWER: 3
<result>C</result>
Glen is having his big family over for Christmas. Out of 25 people coming, 40 percent are lactose intolerant and 72% are vegetarians. Glen wants to prepare the good in advance. Can you calculate how many of the guests are both vegetarians and lactose intolerant?