1. Assuming Tim is willing to incur the same total cost, he can spend an additional $975 on shares of ABC. That will bring his total expenditure on ABC stock to $475 +975 = $1400.
2. If the number of shares he can purchase (n) is proportional to the amount he spends, then
n/1400 = 100/425
n = 1400·100/425 ≈ 329.41
Tim can buy about 329.4 shares of ABC for the same total investment.
3. Since there is no commission on the sale, the amount Tim earns is $2100 -1400 = $700
4. Tim's earnings as a percentage of his investment are
$700/$1400·100% = 50%