Which of these numbers is a multiple of 20?

Write down the first four multiples of 6

Write down the first even multiple of 9

From the list of numbers

1 7 9 12 21 23 30 36 42

Write down all the multiples of 7

The factors of 30 are

1, 2, 3, 5, ?, 10, ? 30

What are the two missing numbers?