If jimmy buys 5 note books for 10.00. How much for 4 notebooks

The inside wheels of a car traveling on a circular path are rotating half as fast as the outside wheels. the front two wheels are six feet apart. what is the number of feet in the path traced by the inside front wheel in one trip around the circle? express your answer in the form "k \pi", where k is an integer.

If 1 is divided by the sum of y& 4. the result is equal to 3 divided by 4 .find the value of m?

What is the missing step in this proof ?