What number is obtained by adding the units digits of 734^99 and 347^83? Choose the correct choice:
A) 7	B) 8	C) 9	D) 10	E) 11

Rationale: the units digit of 734 ^ 99 is 4 because 4 raised to the power of an odd integer ends in 4 . the units digit of 347 ^ 83 is 3 because powers of 7 end in 7 , 9 , 3 , or 1 cyclically . since 83 is in the form 4 n + 3 , the units digit is 3 . then 4 + 3 = 7 . the answer is a .
Answer: A