Answer:
3 necklaces
Explanation:
$40.50-$30.00=$10.50 Subtract her total money and cost of dress
$10.50-$3.50=$6.00 subtract each necklace price from remaining money
$6.00-$3.50=$3.50 keep subtracting price of necklace
$3.50-$3.50=$0 that was 3 necklaces