Mano is making snowballs to build a fort on the winter break. Justin can build 15 snowballs in an hour but 2 snowballs melt every 15 minutes. How long will it take him to build 210 snowballs?
Uh anyone?
Let h stand for hours.
15h - (2*4)h = 210
Solve for h.
To find out how long it will take Justin to build 210 snowballs, we need to calculate the time it takes to build 1 snowball and how many snowballs will melt during that time.
Justin can build 15 snowballs in an hour. Therefore, he can build 1 snowball in 1/15th of an hour or 4 minutes.
Two snowballs melt every 15 minutes. So, in 4 minutes, (4/15) * 2 = 8/15th of a snowball will melt.
Now, let's calculate how many snowballs Justin needs to build to have a total of 210 snowballs minus the amount that melts.
210 snowballs minus the amount that melts (8/15) * 210 = 210 - (8/15) * 210 = 210 - (168/15) = 210 - 11.2 = 198.8
Therefore, Justin needs to build approximately 198.8 snowballs to have a total of 210 snowballs.
Since Justin can build 1 snowball in 4 minutes, he will take 198.8 * 4 = 795.2 minutes or approximately 13 hours and 15 minutes to build 210 snowballs.
So, it will take Justin approximately 13 hours and 15 minutes to build 210 snowballs for the fort.