What should come in place of question mark (?) in the following question?

600 + 300 ÷ 15 = ? × 31

In the following question, select the missing number from the given series.

1, 3, 5, 7, ?

In the following question, select the missing number from the given series.

964, ?, 241, 120.5, 60.25

In the following question, select the missing number from the given series.

24, 26, 28, ?, 32, 34

In the following question, select the missing number from the given series.

9, 11, 14, 16, 19, 21, ?

Choose the correct alternative which will complete the following series:

21, 55, 19, 50, 17, 45, ?

In the following question, select the missing number from the given series.

13, 17, 26, 42, 67, ?

Select the correct option will complete the given number series.

13, 10, 7, 4, ___

In the following question, select the missing number from the given series.

7, 11, 15, 19, 23, ?