Thank you so much!

This question is actually pretty easy! We want to set it up in this formula: a/b = c/d

For this problem:

42/49 = x/21

To find x (or the distance across the river), we need to divide 42 by 49 then multiply it by 21

That gives us x = 18 m

Thank you!

Okay, thanks for trying anyway!

Must be, thanks regardless!