Number System Practice Test 4

We actually need to find the unit place digit of$\left({17}^1\right)\times \left({13}^{17}\right)\times \left({14}^{91}\right)\times {\left(2\right)}^{197}$.
The unit place digit of 17 = 7,
The unit place digit of $\left({13}^{17}\right)=3^{4\times 4}\times 3^1=3$,
The unit place digit of (149) = 9,
The unit place digit of ${\left(2\right)}^{196}=2^{49\times 4}\times 2=2$,
So, the unit place digit of ${17}^1\times {13}^{17}\times {149}^1\times 2^{197}$ $=7\times 3\times 9\times 2=378.$
So, the unit place digit is 8.