Look at this series: 664,332,340,170,?,89,........What number should be placed at (?)

Look at this series: 2, 6, 18, 54, ... What number should come next?

Look at this series: 36, 34, 30, 28, 24, … What number should come next?

Look at this series: 7, 10, 8, 11, 9, 12, ... What numbers should come next?

Look at this series: 21, 9, 21, 11, 21, 13, 21, ... What number should come next?

Look at this series: 7, 10, 8, 11, 9, 12, … What number should come next?

Look at this series: 2, 1, (1/2), (1/4), … What number should come next?

In the following number series, one number is missing. What should come at the place of missing number (?) 20, 29, 54, 103, 184, ?

What is the digit in the unit's place of the number represented by 3^98 - 3^89 ?

The given histogram shows the height of the students The number of students whose height is in the class interval 170-175 is what percent less than the number of students whose height is in the interval 165-170 ? (correct to one decimal place)