Yes he is correct as rational numbers are any numbers, like- 0.5444, -2.8, 7, -3, 1/2, -1/9. Thus, 0.505005000500005 is a rational number as it is a repeating decimal.
Answer:
175lb
Step-by-step explanation:
Let's say 100% - original weight
and 12% - 21lb
weight = (100*21)/12=175lb

The solution of the equations is the coordinates of the point where the two lines intersects, so the required solution is :