The digit in unit's place of the product -
$${\left( {2464} \right)^{1793}}$$ $$ \times {\left( {615} \right)^{317}}$$ $$ \times {\left( {131} \right)^{491}}$$
A. 0
B. 2
C. 3
D. 5
Answer: Option A
Solution(By Examveda Team)
$$\eqalign{ & {\left( {2464} \right)^{1793}} \times {\left( {615} \right)^{317}} \times {\left( {131} \right)^{491}} \cr & {4^1} \to 4 \to 4 \cr & {4^2} \to 16 \to 6 \cr & {4^3} \to 64 \to 4 \cr} $$So, odd power of 4 will have 4 as unit digit and even power of 4 will have 6 as unit digit 5 and 1 have same unit digits respectively.
(2464)1793 have the odd power therefore unit digit is 4
(615)317 have unit digit 5 and
(131)491 have unit digit 1.
i.e Unit digit of the product will be 4 × 5 × 1 = 20.
∴ 0 is the unit digit
Related Questions on Number System
Three numbers are in ratio 1 : 2 : 3 and HCF is 12. The numbers are:
A. 12, 24, 36
B. 11, 22, 33
C. 12, 24, 32
D. 5, 10, 15
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