Answer:
$420
Explanation:
33 1/3% (1/3) of $6,300 is $2,100 so that means Brianna put $2,100 into her savings account, having $4,200 left. Then, if she spent 40% on food and 50% on rent, that means she has 10% (1/10) of her $4,200 left which is $420.
Hope this helps :)