Final answer:
Jaheem's profit for selling 10 pairs of mittens is $25, he must sell at least 7 pairs to break even on the booth rental, and his total profit after renting the booth and selling 20 pairs is $95.
Step-by-step explanation:
A) To calculate Jaheem's profit for selling 10 pairs of mittens, first, find the total revenue by multiplying the selling price per pair by the quantity sold, which is 
$10 × 10 = $100. 
Then, calculate the total cost of making the mittens, which is 
$3 × 10 = $30. 
The profit before booth rental is total revenue minus total cost, i.e., 
$100 - $30 = $70. 
Finally, subtract the booth rental from this profit: 
$70 - $45 = $25.
B) To break even on the booth rental cost of $45, Jaheem must sell enough mittens so that the profit equals the rental cost. Since he makes a profit of $7 ($10 - $3) per pair of mittens, he needs to sell $45 / $7, which is approximately 6.43 pairs. Since Jaheem can't sell a fraction of a pair, he needs to sell at least 7 pairs to break even.
C) If Jaheem sells 20 pairs, his total revenue would be 
$10 × 20 = $200. 
His total cost would be 
$3 × 20 = $60. 
The profit before booth rental is 
$200 - $60 = $140. 
After paying for the booth rental, his total profit would be 
$140 - $45 = $95.