Find the digit at unit's place in the number $17^{1995} + 11^{1995} - 7^{1995}$

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Solution

$17^{n} + 11^{n} - 7^{n}$
$= (10 + 7)^{n} + (10 + 1)^{n} - 7^{n}$
Units place = $10 k + 7^{n} + 10 m + 1 - 7^{n}$
$= 10 (k + m) + 1$
Hence unit digit will be $1.$

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Find the digit at unit's place in the number 171995+111995−71995

17n+11n−7n=(10+7)n+(10+1)n−7nUnits place =10k+7n+10m+1−7n=10(k+m)+1Hence unit digit will be 1.

Find the digit at unit's place in the number $17^{1995} + 11^{1995} - 7^{1995}$

$17^{n} + 11^{n} - 7^{n}$
$= (10 + 7)^{n} + (10 + 1)^{n} - 7^{n}$
Units place = $10 k + 7^{n} + 10 m + 1 - 7^{n}$
$= 10 (k + m) + 1$
Hence unit digit will be $1.$