3. What are the missing numbers in the sequence 6, 11, 9, 14, ____, 17, ____?
4. In a mini theater, the first row has 8 seats, the second row has 10, and the third row has 12. If there are 20 rows in the theater, which row has 38 seats? How many seats are there in all?
5. A pile of blocks has 40 blocks in the bottom row, 36 blocks in the second row, 32 blocks on the third row and so on until there are only 4 blocks on the top row. How many blocks are there in the 7th row? How many blocks are there in all?
