Math, asked by ritiktidke9, 7 months ago

In an A.P a=2, An=40 and Sn=420 then n is

Answers

Answered by Akleshmourya8810

2

Answer:

20

Step-by-step explanation:

An = l

Using formula Sn = n(a+l) /2

420 = n(2+40)/2

420/21 = n

N = 20

Answered by neerajaponnu8

2

Step-by-step explanation:

a is the first term

an is the last term

so by using sn=n/2(a+l)

Attachments:

Previous Question

Next Question

Similar questions

Science, 3 months ago

list change in the body that take place at puberty ?

Hindi, 3 months ago

please tell the answer fastly...

Math, 3 months ago

in a parallelogram abcd opposite angles are(3x-50) °and (x+40) °...

Geography, 7 months ago

किसी एक मंडल के न होने से क्या-क्या कठिनाईयाँ होगी।...

Social Sciences, 7 months ago

period of one complete rotation of the earth...

English, 11 months ago

What is anecdotal evidence?

Computer Science, 11 months ago

def table(x): c=range(1,11) d=[i*x for i in c] return d #this is my defined function my_nums=[1,2,3,4,5,6,7,8,9,10,11] i/p>>>> list(map(table,my_nums)) o/p>>>[[1, 2, 3, 4, 5, 6, 7, 8, 9, 10], [2, 4, 6, 8, 10, 12, 14, 16, 18, 20], [3, 6, 9, 12, 15, 18, 21, 24, 27, 30], [4, 8, 12, 16, 20, 24, 28, 32, 36, 40], [5, 10, 15, 20, 25, 30, 35, 40,...

Geography, 11 months ago

prove Schrodinger's equation...