(A) P = Q – k
(B) P = Q + k
(C) P = Q
(D) P = Q +2 k答案： (A)
解释：
P is sum of odd integers from 1 to 2k
Q is sum of even integers from 1 to 2k
Let k = 5
P is sum of odd integers from 1 to 10
P = 1 + 3 + 5 + 7 + 9
Q is sum of even integers from 1 to 10
Q = 2 + 4 + 6 + 8 + 10
In general, Q can be written as
Q = (1 + 3 + 5 + 9..... ) + (1 + 1 + .....)
= P + k
这个问题的测验