There are two pieces of sticks. One has a length of 63 cm and another with a length of 42 cm. They are cut into equal pieces of length without any remainder. Find the greatest possible length that the pieces can be.
Billie wants to make bags full of goodies for his birthday. He has 40 mini gumball toys, 30 vanilla lollipops, 10 premium chocolates, 20 ice gums. He wants his visitors to have the same amount in each bag. What is the greatest number of bags can Billie make?