Question:
51+50+49+ ..... + 21= .....
A1116
B1122
C1128
D1124
Answer:
A. 1116
Explanation:
a=51,d=-1 അവസാന പദം=21 n=((21-51)/-1)+1 =31 Sn=31/2*(2a+30d) =31/2(102-30) =1116
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Question:
A1116
B1122
C1128
D1124
Answer:
a=51,d=-1 അവസാന പദം=21 n=((21-51)/-1)+1 =31 Sn=31/2*(2a+30d) =31/2(102-30) =1116
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