The total cost would be $991.
The number of attendees would be 4.
Explanation:
Let 'x' be the number of attendees,
- Total cost = Reservation + cost of all attendees.
- Total cost of 1st Hotel = $823 + $42x
- Total cost of 2nd Hotel = $663 + $82x
To have the venues cost the same amount,
$823 + $42x = $663 + $82x
⇒ $823 - $663 = $82x -$42x
⇒ 160 = 40x
⇒ x = 160/40
⇒ x = 4 attendees.
Substitute x=4 to find the total cost.
⇒ $823 + $42(4) = $991
⇒ $663 + $82(4) = $991
∴ The cost for the two venues are same.