Question

Find the 20th term of the sequence. 1600, 1200, 900, ...

Answer 1

First approach :

The above series can be seen as

1600 , (1600–400) 1200, (1200–300) 900 .

So we see that the values are getting decreased by 400,300 respectively.

Hence the next term in the sequence will be 900–200 = 700.

Other approach could be :

A geometric progression with ratio as 3/4.

1600*(3/4) = 1200

1200*(3/4) = 900

900*(3/4) = 675

Taking the above two approaches in mind,the two possible answers could be 700 or 675

Um- here ya go