# If D varies directly with the square root of e and D=424 when e=64, what is the value of D when e=625?
# Hi @turbid arrow the answer is 1325 = 53 * 25 as 424 = 53 * 8 and 64 = 8 * 8 as well as 625 = 25 * 25
# In this context direct variation of D from square root of e means that $D = k \cdot \sqrt{e}$ for some $k$