Math, asked by banku2, 1 year ago

solve the arithmetic progression

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Answers

Answered by charumathi1
3
Sn=n/2 [2a+(n-1)d] (Sn=1050)
S14=14/2 [2×10+(14-1)d]
1050=7 (20+13d)
1050=140+91d
910=91d
d=10

a20=a+19d
=10+19×10
=200

hence 20th term is 200.



Answered by mysticd
3
Hi ,

Let a , d are first term and common

difference of an A.P

Sum of ' n ' terms = Sn

Sn = n/2 [ 2a + ( n - 1 )d ]

According to the problem given ,

S14 = 1050 , a = 10

14/2[ 2× 10 + ( 14 - 1 ) d ] = 1050

20 + 13d = 1050/7

13d = 150 - 20

13d = 130

d = 130/13

d = 10

Therefore ,

20th term in A.P = a + 19d

t20 = 10 + 19 × 10

= 10 + 190

= 200

I hope this helps you.

: )
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