Look at this series: 53, 53, 40, 40, 27, 27, ... What number should come next?

Look at this series: 53, 53, 40, 40, 27, 27, ... What number should come next?

2) 165, 195, 255, 285, 345, ?

3) Look at this series: 22, 21, 23, 22, 24, 23, ... What number should come next?

4) 2, 3, 6, 15, ?, 123

5) In the following number series a wrong number is given. Find out the wrong number.
1, 3, 10, 21, 64, 129, 356, 777