Answer:
twice the number of 30 second ads = the number of 60 second ads
Step-by-step explanation:
I can not see much work done for explanation of the error, but
let x be the ad pf 30 second
y be the ad of 60 second
so both add together will make 12 minutes, so by counting the time in seconds we will multiply 12 by 60 so we will have a equation
x +y = 12 x 60
x+y = 720 ----------1
as x is 30 second so we can say y = 2x---------- equation 2
adding value of y in equation 1
x+ 2x= 720
3x= 720
x= 720/3= 240
adding value of x in equation 2
y= 2(240)
y= 480
so from equation 1 and 2., x = 240 y =480
