If the productivity of a brigade grows by 20% when the number of the workers in the brigade is increased by one, then which of the following is closest to the ratio of the productivity of a 12-person brigade to that of a 10-person brigade? Choose the correct choice from the following choices:
A) 0.21	B) 0.82	C) 1.31	D) 1.21	E) 1.44
B = 10-men brigade   p = increase in the productivity = 20%   Solution: B x p = B x 1.2 = 1.2B -------&gt; the productivity of 11 men brigade   1.2B x p = 1.2B x 1.1 = 1.31B -----&gt; the productivity of 12 men brigade   The ratio of the productivity of a 12-men brigade to that of a 10-men brigade = 1.31B/B = 1.31   1.31
<result>C</result>
If the productivity of a brigade grows by 20% when the number of the workers in the brigade is increased by one, then which of the following is closest to the ratio of the productivity of a 12-person brigade to that of a 10-person brigade?