Tom lived 3 miles from his school. if he rode his bike 3/8 of the distance and then walked the rest, how far did he ride his bike?

Pls! does anybody know a shortcut for answering these types of questions in the future?

Prove the divisibility of the following numbers: 25^9 + 5^7 is divisible by 30.also, read as (25 to the power of 9) + (5 to the power of 7) is divisible by 30. blank x 30what is the blank? ( it should be expressed in exponent form)

What is the greatest number of parts of a circle that can be formed by cutting the circle with 7 straight cuts? (note: the parts do not have to be equal in size)