Question

Find the sum of all numbers from 50 to 350 which are divisible by 6 hence find the 15th term of that a.p.

Answer 1

Here is the answer of this question

you can check it out its a picture hope this will help you......

Answer 2

Answer:

The sum of all numbers from 50 to 350 which are divisible by 6 is 10050 and he 15th term is 138.

Step-by-step explanation:

We have to find sum of all numbers from 50 to 350 which are divisible by 6.

The required AP is

54, 60, ..., 348

Here first term is 54 and common difference is 6.

The nth term is defined as

$a_n=a+(n-1)d$

$348=54+(n-1)6$

$348=54+6n-6$

$300=6n$

$n=50$

The number of terms in AP is 50.

The sum of n terms is defined as

$S_n=\frac{n}{2}[2a+(n-1)d]$

$S_{50}=\frac{50}{2}[2(54)+(50-1)6]=10050$

The sum of all numbers from 50 to 350 which are divisible by 6 is 10050.

15 th term of that A.P. is

$a_{15}=54+14(6)=138$

Therefore the 15th term is 138.