Sandra's retirement party will cost $10 if she invites 5 guests. If there are 13 guests, how much will Sandra's retirement party cost? Solve using unit rates.

$26

Step-by-step explanation:

10/5=2

That means that it costs $2 for each guest.

So 13x2=26

It will cost Sandra $26 if she invites 13 guests to her party.

  15π m

Step-by-step explanation:

Short arc AC is 60°, so long arc ADC will be 360°-60° = 300°. As a fraction of the circumference of the circle it is

  (300°/360°)C = 5/6C

where C is the circumference:

  C = 2πr = 2π(9 m) = 18π m

Then the arc length is ...

  arc ADC = (5/6)(18π m) = 15π m