eric has a riddle: " i am thinking of a fraction that is equivalent to 2/5 and the numerator is 18 less than the denominator." what is his fraction explain how you know.​

12/30

Step-by-step explanation:

So we know that the denominator-numerator=18

And we also know that it's equal to 4/10 or 2/5.

S the most easiest is just to trial and error: 12/30

But I don't really know the more complex formula...

b. 24 mm

step-by-step explanation:

use the pythagorean theorem.

a^2 + b^2 = c^2

a^2 + 7^2 = 25^2

a^2 + 49 = 625

a^2 = 576

a = 24

answer: b. 24 mm