Minnie is making a playlist of songs for a party she will be throwing. She wants the playlist to be an hour long. She has added 16 three-minute songs to the playlist. How many four-minute songs does she have to add to make sure the playlist is an hour long?
An hour is equal to 60 minutes.
Minnie has 16 * 3 = 
<gadget id="calculator">16*3</gadget>
<output>48</output>
48 minutes of songs already on the playlist.
She has to fill 60 - 48 = 
<gadget id="calculator">60-48</gadget>
<output>12</output>
12 more minutes.
Thus, she needs to add 12 / 4 = 
<gadget id="calculator">12/4</gadget>
<output>3</output>
3 four-minute songs.

<result>3</result>