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Algebra!

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Algebra!

by Ahmed MS » Wed Apr 06, 2011 8:44 pm
Hi, Can anyone help me to solve this problem with explanation.

(13)^4×(17)^2×(29)^3
What is the unit digit of above?
Answer Options:
a. 9,
b. 7,
c. 5,
d. 3,
e. 1
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by manpsingh87 » Wed Apr 06, 2011 8:48 pm
Ahmed MS wrote:Hi, Can anyone help me to solve this problem with explanation.

(13)^4×(17)^2×(29)^3
What is the unit digit of above?
Answer Options:
a. 9,
b. 7,
c. 5,
d. 3,
e. 1
IMO E

while solving such question only consider he last digit of the number, for example in 13 we have to consider only 3, as question asks about 13^4,therefore 3^4=81, which again consider the last digit which is 1, similarly 17^2, 7^2=49 considering last digit we have 9, and for 29^3 , 9^3=9

therefore required answer is 1*9*9=81 again considering last digit we have 1
hence E
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by Ahmed MS » Wed Apr 06, 2011 9:13 pm
Thanks a lot!
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