Capgemini
Company
Numerical Ability
Sequence and Series
The sum of first 20 numbers in an A.P. is equal to the sum of first 30 numbers. Find the sum of first 50 numbers of the A.P.?
Read Solution (Total 3)
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- Sum = (n/2)(2a + (n - 1)d)
(20/2)(2a + 19d)= (30/2)(2a + 29d)
20a + 190d = 30a + 435d
10a = - 245d
a =( - 49/2) d
Sum of 50 first terms = 25(-49d +49d)= 0 - 12 years agoHelpfull: Yes(66) No(9)
- Zero...this is math subject direct theorem
- 9 years agoHelpfull: Yes(4) No(5)
- It should be zero
- 7 years agoHelpfull: Yes(1) No(2)
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