Question

21st term of sequence 16,11,6..

Answer 1

Answer:

-84

Step-by-step explanation:

Sequence : 16, 11, 6, 1, .....

We can see that is an Arithmetic Progression (AP) with

First Term (a) = 16

Common Difference (d) = -5

Using the Formula of General Term of an AP

$t_{n} = a + (n-1)\:d\\\\\mathrm{Where}\:t_{n}\:\mathrm{denotes\;the\;n^{th}\;term}\\\\\mathrm{Substituting\:n = 21\;and\;values\:of\:a\:and\:d}\\\\=> t_{21} = 16 + (21 - 1)\:(-5)\\=> t_{21} = 16 + (20)\:(-5)\\=> t_{21} = 16 - 100\\=> t_{21} = -84$