Rewrite (log480-log3) +2log25 as a single logarithmic. then evaluate the simple logarithmic

Mat bought a phone for $100. he has to pay $30 per mouth. if he has paid $640 in total, how many mouth has he had the phone?

There are 45 questions on your math exam. you answered 810 of them correctly. how many questions did you answer correctly?

Avery’s piggy bank has 300 nickels, 450 pennies, and 150 dimes. she randomly picks three coins. each time she picks a coin, she makes a note of it and puts it back into the piggy bank before picking the next coin.