30% of 700 = 210
Using a 3x3 matrix and plotting these two pieces of information:
\begin{tabular}{|l|l|l|l|}
\hline
~ & HD & nHD & Total \\ \hline
40+ & 210 & ~ & ~ \\ \hline
n40+ & ~ & ~ & ~ \\ \hline
Total & ~ & ~ & 700 \\ \hline
\end{tabular}
(1) 55% of the televisions measure more than 40 inches diagonally.55% of 700 = 385
Filling this in and doing any calculations which can be done:
\begin{tabular}{|l|l|l|l|}
\hline
~ & HD & nHD & Total \\ \hline
40+ & 210 & 175 & 385 \\ \hline
n40+ & ~ & ~ & 315 \\ \hline
Total & ~ & ~ & 700 \\ \hline
\end{tabular}
Without further information it is impossible to determine the number of the flat screen televisions which are offer HD and are 40 inches or smaller in size.
INSUFFICIENT(2) 105 of the television are 40 inches or smaller and do not offer high-definition.Filling in the information from this statement and doing any calculations which can be done:
\begin{tabular}{|l|l|l|l|}
\hline
~ & HD & nHD & Total \\ \hline
40+ & 210 & ~ & ~ \\ \hline
n40+ & ~ & 105 & ~ \\ \hline
Total & ~ & ~ & 700 \\ \hline
\end{tabular}
Without more information it is impossible to solve for the number of the flat screen televisions which are HD and are 40 inches or smaller in size.
INSUFFICIENT(1+2)Combining the two tables will yield:
\begin{tabular}{|l|l|l|l|}
\hline
~ & HD & nHD & Total \\ \hline
40+ & 210 & 175 & 385 \\ \hline
n40+ & ~ & 105 & 315 \\ \hline
Total & ~ & ~ & 700 \\ \hline
\end{tabular}
From here it is easy to solve for the number of the flat screen televisions which are HD and are 40 inches or smaller in size: \(315-105=210\)
SUFFICIENT
ANSWER C