If x is a positive integer, what is the units digit of (24)^(2x+1)(33)^(x+1)(17)^(x+2)(9)^(2x)	Select the correct option: A) 4 B) 6 C) 7 D) 8 E) 9
To find the units digit of the above (24)^(2x+1)(33)^(x+1)(17)^(x+2)(9)^(2x) , find the units digit of each term possible .   24^2x . 24 --&gt; Units digit of (24^2)^X = 6^X = 6 multiplied by last digit of 24 = 4   33^x . 33 --&gt; Units digit of 33^x . 3 --&gt; 3,9,7,1 multiplied by 3   17^x. 17^2 --&gt; Units digit of 17^x. 9 (units digit of 7^2)--&gt; 7,9,3,1 multiplied by 9   9^2x --&gt; Units digit of 81^x = 1   If you observe 2nd and 3rd expression above and multiply both you will always get 1 for units digit of 33^x multiplied by 17^x ( because 3*7, 9*9,7*3,1*1 all end in 1 for the same value of x) . Thus you have 3 and 9 from 2nd and third expression above.   So the units digit of the whole expression = Units digit of 4*3*9*1 which is 8 .   Answer Choice 8
<result>D</result>
If x is a positive integer, what is the units digit of (24)^(2x+1)(33)^(x+1)(17)^(x+2)(9)^(2x)