Grand canyon tours offers air and ground scenic tours of the grand canyon. tickets for the 7-1/2 hr tour cost $169 for an adult and $129 for a child, and each tour group is limited to 19 people. on three recent fully booked tours, total receipts were $2931 for the first tour, $3011 for the second tour, and $2771 for the third tour. determine how many adults and how many children were in each tour. hint: use method of question 2 to find the number of adults and children in each tour (3 tours).