the sum of all natural Numbers between 200 and 400 which are divisible by 7 is
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Answered by
6
Hey!!!
Required AP : 203, 210, 217 .. 399
Thus
a = 203
d = 7
l = 399
n = ?
l = a + (n - 1)d
=> 399 = 203 + (n - 1)7
=> (n - 1)7 = 196
=> n - 1 = 28
=> n = 29
S29 = n/2(a + l)
=> 29/2( 203 + 399 )
=> 29/2(602)
=> 29 x 301
=> 8729
Hope this helps
Required AP : 203, 210, 217 .. 399
Thus
a = 203
d = 7
l = 399
n = ?
l = a + (n - 1)d
=> 399 = 203 + (n - 1)7
=> (n - 1)7 = 196
=> n - 1 = 28
=> n = 29
S29 = n/2(a + l)
=> 29/2( 203 + 399 )
=> 29/2(602)
=> 29 x 301
=> 8729
Hope this helps
Answered by
1
203,210,217..........399
an=a+(n-1)d
399=203+(n-1)7
399-203=(n-1)7
196/7=n-1
28=n-1
n=29
Sn=n/2(a+an)
S=29/2(203+399)
S=29/2(602)
S=29(301)
S=8729
an=a+(n-1)d
399=203+(n-1)7
399-203=(n-1)7
196/7=n-1
28=n-1
n=29
Sn=n/2(a+an)
S=29/2(203+399)
S=29/2(602)
S=29(301)
S=8729
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