Mr. Jones sold two pipes at $\textdollar{ 1.20}$ each. Based on the cost, his profit on one was
$20$% and his loss on the other was $20$%. 
On the sale of the pipes, he: 
$\textbf{(A)}\ \text{broke even}\qquad \textbf{(B)}\ \text{lost }4\text{ cents} \qquad\textbf{(C)}\ \text{gained }4\text{ cents}\qquad \\ \textbf{(D)}\ \text{lost }10\text{ cents}\qquad \textbf{(E)}\ \text{gained }10\text{ cents}$
For the first pipe, we are told that his profit was 20%. In other words, he sold the pipe for 120% or $\frac{6}{5}$ of its original value. This tells us that the original price was $\frac{5}{6}\cdot1.20 = $1.00$.
For the second pipe, we are told that his loss was 20%. In other words, he sold the pipe for 80% or $\frac{4}{5}$ of its original value. This tells us that the original price was $\frac{5}{4}\cdot1.20 = $1.50$.

Thus, his total cost was $$2.50$ and his total revenue was $$2.40$.

Therefore, he $\boxed{\textbf{(D)}\ \text{lost }10\text{ cents}}$.