Tricks for Solve Series Questions in Reasoning Quickly

Series questions are asked in almost all the competitive examination in reasoning section. So it is very important for a candidate who is preparing for competitive exams to solve series problems as quickly as possible and also as accurately as possible. So here are some of the tricks that will give you some idea on how to solve these questions quickly.

You have to follow the below given steps in order to solve the given series in shortest possible time.

Step 1: check the series to see whether it is decreasing or increasing or alternating.

Step 2: do this step if the series is increasing or decreasing.

Check to see if the series in increasing gradually or slowly. If it is so, then it might be an addition series.

However if the series is rising sharply but slows down later, then there is more chances that the series might be formed by squared or cubed numbers. But if the series is equally sharp throughout, then there are more chances that the series is multiplication based (with or without addition or subtraction). The same idea also applies when the series is decreasing (vice-versa).

If the rise of the series is irregular, then there might be a mix of two series going alternately.

Now let us apply the above ideas to solve some example questions of series.

Find the next number in the series?

16, 17, 21, 30, 46, ?

You can see that the series is increasing first by 1, then by 4, then by 9, then by 16. So the series is rising sharply. It means it
should be a series of squared or cubed numbers added at each step. Also when you look at the difference of numbers (1,4,9,16, ?), you can easily figure out that the difference of numbers are the squares of normal number series i.e. 1,2,3,4,?. So according to number series, 5 should come after 4. When we square
5, it equals 25. So we add 25 to 46 which equals 71. So 71 should be the next number in the series.

Now let us take another example.

Find next number in -2, 4, 22, 58, 118, ?

Solution: as you can see the series increases sharply in the start when it goes from 4 to 22, but then it slows down in the last. So it is more likely to be a series in which addition of squared or cubed numbers is
done. Also there is a minus number in the series (-2), so it means there might be something deducted from the series.

Upon checking the speedy rise, we can figure out that the series increases by the below given pattern.

(1^3)-3= -2

(2^3)-4= 4

(3^3)-5= 22

(4^3)-6= 58

(5^3)-7= 118

(6^3)-8= 208

So 208 should be the next number in the series.

NOTE: it is very important to practice series question as much as you can.