Problem:
2−2+2−3+2−421+20+2−1​ equals
Answer Choices:
A. 6
B. 8
C. 231​
D. 24
E. 512
Solution:
By inspection, we see that the fraction is of the form
a+b+c8a+8b+8c​=a+b+c8(a+b+c)​=8
Or, compute
221​+231​+241​2+1+21​​=41​+81​+161​27​​=167​27​​=8