Answer:
Yes
Explanation:
Hi, the expression is correct.
Since she wants to price (p) her used books with a 50% gross profit, to do this she has to multiply the cost of the books (c ) by a percent increase (1 + %/100).
So, for a 50% gross
p = (1 + 50/100) c = (1+ 0.5 )c
p= 1.5c
Feel free to ask for more if needed or if you did not understand something.