Final answer:
Each friend owes $10.50 and they will receive $7 in change if they pay with $70 cash.
Step-by-step explanation:
To calculate how much money each friend owes, divide the total bill by the number of friends. In this case, the total bill is $63 and there are 6 friends, so each friend owes $63 / 6 = $10.50.
To calculate how much change they will receive if they pay with $70 cash, subtract the total bill from the amount of cash. In this case, the total bill is $63 and they pay with $70, so they will receive $70 - $63 = $7 in change.