Which one of these grids is shaded red and blue in the ratio 1 : 1/3?
A
B.
C
E

A proportion is simply a statement that two ratios are equal. It can be written in two ways: as two equal fractions a/b = c/d; or using a colon, a:b = c:d. The following proportion is read as "twenty is to twenty-five as four is to five."

Explanation:

answer; indirect elisa;