A couple of years ago during the playoffs, a network sold 30-second ads for $175,000 and 60-second ads for $250,000. If they sold 13 commercial spots and earned $2,650,000, how many of each type of commercial spot did they sell?

Guest Apr 18, 2017

#1**0 **

you can write this into an equation

# of 30 second ads= x

# of 60 second ads= y

x+y=13

x175,000+y250,000 = 2,650,000

we can turn x+y=13 into x=13-y

and replace x in the second one with such

giving us y250,000 - y175,000 + 2,275,000 = 2,650,000

by subtracting 2,275,000 from both sides and simplifying the left side we are given

y75,000 = 375,000

divide both sides by 75,000

y=5

now we plug that into x+y=13

x+5=13

subtract 5 from both sides

x=8

which means 8 30 second ads, and 5 60 second ads.

Guest Apr 18, 2017