Dan has some marbles. ellie has twice as many marbles as dan. frank has 15 marbles. dan, ellie and frank have a total of 63 marbles. how many does dan have

At a local museum, the total price for one adult and one child is $11. mrs. smith paid for herself and her three children. she spent $19. record the system of equations to be solved and then find the price of an adult and child ticket using either elimination or substitution.