Adult Tickets & Child Tickets - in {dollar, ticket} space

the two Adult Tickets & Child Tickets applets allow the user to explore the same problem in two different graphical representations Tickets for a minor league baseball game cost $10 for an adult and $4 for a child. A total of 400 tickets were sold and $3,400 was collected. How many adult tickets were sold and how many children’s tickets were sold? Now make up (and solve) two other similar problems. Explain what makes the new problems similar. Explain how this problem is similar to the ones in the ‘Coin problem’ environment and the ‘Coffee mixture’ environment