Math, asked by Krishna11123, 1 year ago

The first term of an AP is 5, the last term is 45 and the sum is 400. find the number of terms and the common difference.

Answers

Answered by Anonymous
10
Here is your answer :-

We know that,

Sⁿ = n/2 ( a + l )

Where,

Sⁿ = sum of n terms.
a = first term
l = last term.
n = number of terms.

A/q,

400 = n/2 ( 5 + 45 )

➡ 400 = n/2 ( 50 )

➡ 25n = 400

➡ n = 400/25

➡ n = 16.

So, numbers of in this AP is 16.

Hope it will help you !!!
Answered by nainjatt10
5
a = 5
l = 45 
sum = 400
sum = n/2 (a +l)
400  = n/2 (5+45)
800  = 50n
 n     = 800/50
 n     = 16
 
 therefore no. of terms = 16 ------------------ANSWER 

tiyuyopb14k0: Where is common difference sir
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