Find the sum of 3+33+333+...upto n terms of an Ap
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Answer:
This example has up to 12 terms available .
Step-by-step explanation:
The question is 3+33+333+…..12 terms. We can write it as
3(1+11+111+….12 terms)
=(3/9)(9+99+999+….12 terms)
=(3/9)((10 - 1) + (100 - 1) + (1000 -1)…12 terms) we can use the geometric series summation here.
=(3/9)(10)(10^12 - 1)/9) - (3/9)(12)
=(10(10^12–1)/27) - 4
=(9999999999990/27) - 4 = 370,370,370,366
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