A group of boys stood in three rows. The 1st row had 6b boys. The 2nd row had 4b fewer boys than the 1st row. The 3rd row had 3 more boys than the 2nd row.
- Find the number of boys in the 3rd row in terms of b. Give your answer in the simplest form.
- There were 21 boys in the 3rd row. Find the value of b.