Answer:
Each undershirt costs $2.99 when purchased individually.
Step-by-step explanation:
The problem says that $13.98 is $3.96 less than the cost of buying 6 individual shirts which means that the total cost of buying 6 individual shirts is $17.94.
To find the price of 1 individual shirt, you divide 17.94 by 6. When you do this, you get $2.99. $2.99 is the cost of each undershirt when purchased individually.
Hope this helps!