BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Algebra!

Expert replies
Source: — Problem Solving |

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
O Excellence... my search for you is on... you can be far.. but not beyond my reach!
Join the discussion

by Ahmed MS » Wed Apr 06, 2011 9:13 pm
Thanks a lot!
Join the discussion