Essam traced his ruler on graph paper. He kept the edge of the ruler on the paper while he flipped the ruler over. Then, he traced the ruler again. What type of transformation did he perform? Group of answer choices

A. rotation

B. duplication

C. translation

D. reflection

Please help me

With math question will mark brainliest question in the pic.

One-third of the people from country a claim that they are from country b, and the rest admit they are from country a. one-fourth of the people from country claim that they are from country a, and the rest admit they are from country b. in a combined census of the two countries, one-half of the total claimed to be from a. what is the ratio of the populations of country a to that of country b.

Find and simplify an expression for the area of five rows of x squares with side lengths of x centimeters.