we have two ratio
11/12 and 28/31
this can be determine by equating the two fractions
11/12 = 28/31
introduce cross multiplication
11 x 31 = 12 x 28
341 = 336
The following ratios are not equivalent ratios because they are not equal to each other
341 is not equal to 336
The answer is the pair of the ratios are not equivalent ratios