In the sum $\otimes + 1\otimes + 5\otimes + \otimes\otimes + \otimes 1 = 1\otimes\otimes$ for which digit does the symbol $\otimes$ stand?

Question

Aicharya · Accepted Answer

Let $\otimes = d$. The terms are: $d$, $10+d$, $50+d$, $11d$ (since $\otimes\otimes = 10d+d$), and $10d+1$. Sum $= d + (10+d) + (50+d) + 11d + (10d+1) = 24d + 61$. The right side $1\otimes\otimes = 100 + 11d$. Setting equal: $24d + 61 = 100 + 11d$, so $13d = 39$, $d = 3$.

In the sum $\otimes + 1\otimes + 5\otimes + \otimes\otimes + \otimes 1 = 1\otimes\otimes$ for which digit…

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