Question 55

The unit’s digit of $$3^{1001} \times 7^{1002} \times 13^{1003}$$ is

Solution

Expression : $$3^{1001} \times 7^{1002} \times 13^{1003}$$

= $$3^{4k+1} \times 7^{4k+2} \times 13^{4k+3}$$

Unit's digit will be same as unit digit of $$(3)^1\times(7)^2\times(3)^3$$

Only unit digit considered = $$3\times9\times7=9$$

=> Ans - (D)


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