The following are the choices on this question:
A.6
B. 39
C. 26
D. 12
The answer is option D. 12.
Check this out:
S=n² + n
S= 12² + 12
(you can get the square of 12 by multiplying 12 by itself: 12 × 12)
S=144 +12
S=156
40%= 0.40 if you think of the decimal being at the end of the number (40.%) than just move the decimal twice makes it 0.40
maybe 28 is the answer...
