The Daily Info charges a fee of $650 plus $80 per week to run an add. The People's Paper charges $145 per week. For how many weeks must an ad run for the total cost at the Daily Info to be less expensive than the cost at the People's Paper?

Step-by-step explanation:

let the total cost be y

and let the number of weeks be x

Daily Info charges

y=650+80x1

People's Paper charges

y=145x2

equating 1 and 2 to solve for x we have

650+80x=145x

650=145x-80x

650=65x

x=650/65

x=10

Therefore the answer is 10 weeks

in counting the number of heads in 4 coin flips, the probability that we get exactly one head is the probability that we get anyone of the following 4 outcomes: httt, thtt, ttht, or ttth. each has probability 1/16, so the probability to get exactly one head in 4 flips is 1/16 + 1/16 + 1/16 + 1/16 = 4/16 = 1/4.