Vlad did not make a mistake.
Answer:
$1,500
Step-by-step explanation:
I = PRT
I = 10,000 × .03 x 5
I = $1,500
use 
to get 
then use
and 
also, 
to get 
then again use the first identity In both pairs, i.e.

to get 
multiply and divide by 4 to get the RHS.
because, 
squaring both sides, 
294.34 I think this is the answer but I’m not fully sure