Question

77, 90, 109, 140, 189, ?.plz ans​

Answer 1

Given series:-

77, 90, 109, 140, 189, ?

To find:-

The next term in the series.

Solution:-

If we look at the difference between the term and the term next to it, we get something as follows:-

90-77 = 13

109-90 = 19

140-109 = 31

189-140 = 49

? - 189 = x

The differences are: 13, 19, 31, 49 and x.

Let this be another series.

Now, again:

13 + 6 = 19

19 + 12 = 31

31 + 18 = 49

Similarly, 49 + 24 = 73

The bold numbers are the increasing multiples of 6.

Now, we find that in the series: 13, 19, 31, 49, x  

x = 73

Here, we put the value of 'x' and hence the required value can be operated as follows:

? - 189 = 73

⇒? = 73 + 189 = 262

$\large\boxed{\fcolorbox{blue}{yellow} {\implies ?=262}}$