As you multiply by the increasing powers if 10,how does the position of the decimal point chnage in the product me quickly plz

Adam used 1072.4 gallons of water over the course of 7 days. how much water did adam use, on average, each day?

The cost of a taxi ride includes an initial charge of $2.00. if a 5km ride cost $6.00 and a 10km ride cost $10.00, determine the cost of a 15km ride.

Evan went to the park and saw for animals each animal was either a duck or dog if he saw a total of 14 legs how many of each animal did he see