FIND THE SUM OF ALL TWO DIIT NATURAL NUMBER WHICH ARE DIVISIBLE BY 9
Answers
Answered by
1
Answer:
18+27+36+45+54+63+72+81=396
Answered by
0
Answer:
585
Step-by-step explanation:
9a=9×2=18
9×3=27 , 9×11=99
18+ 27+36+.............+99
a=18 d=9 l=99
l=a+(n-1)d
99=18+(n-1)×9
99=18+9n-9
99-9=9n
90=9n
n=10
S=n/2 (a+l)
S=10/2 (18+99)
S =5×117=585
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