Without adding find the sum:
(I) 1+3+5+7+9+11
(ii) 1+3+5+7+9+11+13
Answers
Answered by
1
Answer:
1) 36
2)49
Hint => first add those numbers which will make 0 in ones place.
Jai Shree Ram
Answered by
1
Answer:
i) here, a=1, d=3-1=2, n=6 and l=11
so, 1+3+5+7+9+11 = n/2(a+l)
= 6/2(1+11) = 3×12 =36.
ii) here, a=1, d=3-1=2, n=7 and l=13
so, 1+3+5+7+9+11+13 = n/2(a+l)
= 7/2(1+13) = 7/2(14) = 7×7 = 49.
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