How to flip a desk 5 feet long and then flip another desk and it was 10 feet long what would be the answer

Tyler enjoys the fish so much that after his birthday his family decides to take him to a famous aquarium a tank at the aquarium is similar to his tank with the scale factor of 8 how many times greater is the volume of the tank at the aquarium than the volume of tyler tank

Can you me find the missing length. i attached an image.

Adeposit of 5500 at 6% for 3 years equals