In following question, a number series is given with one term missing. Choose the correct alternative that will same pattern and fill in the blank spaces. -
11 * 1 / 9, 12 * 1 / 2, 14 * 2 / 7, 16 * 2 / 3,
In following number series, two terms have been put within brackets. Choose the appropriate option - Look at this series: 21, 9, 21, 11, 21, 13, . . .What number should come next?