A group of children stood in three rows. The 1st row had 6t children. The 2nd row had 7t more children than the 1st row. The 3rd row had 5 less children than the 2nd row.
- Find the number of children in the 3rd row in terms of t. Give your answer in the simplest form.
- There were 21 children in the 3rd row. Find the value of t.