CBSE Class 10 Answered
find the number of terms if:2+4+6+8+......=10100
Asked by riyaliz | 22 Jul, 2008, 10:13: PM
Expert Answer
a = 2, d = 2
sum of n terms = n/2 [2a +(n-1)d]
10100 = n/2 [4 +(n-1)2]
10100 = 2n + n(n-1)
n2 - n + 2n -10100 = 0
n2 +n -10100 = 0
n2 + 101n -100n -10100 = 0
n(n+101) -100(n+101)=0
(n-100)(n+101)=0
n = 100 or n = -101 (negative number of terms is not possible )
n = 100
Answered by | 23 Jul, 2008, 09:10: PM
CBSE 10 - Maths
Asked by hanugraha | 30 May, 2010, 07:53: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by hanugraha | 30 May, 2010, 07:13: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by shobhitdc | 29 May, 2010, 04:59: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by ROJAAPPA | 29 May, 2010, 12:58: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by shobhitdc | 29 May, 2010, 10:52: AM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by devanshmudgal | 28 May, 2010, 07:31: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by shobhitdc | 28 May, 2010, 01:12: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by shobhitdc | 28 May, 2010, 01:08: PM
ANSWERED BY EXPERT