The publisher from needs to change his calculations. before the book is actually produced, rising paper costs increase variable costs to $2.10 per book. if the company wants to start making a profit at the same production level as before the paper cost increase,
for how much should they sell the book now?

As the variable cost increased by $2.10 per book so if publisher wants to start making profit at same level of production then it should increase the selling price of the book by $2.10. As the increase in cost and selling price will be same so the publisher will also start making profit at same production level.

hi : ) i found this so i hope this !

"we first find value of tax in dollars.

the difference between the two prices   is: 23. 54 - 22 = 1.54

therefore the sales tax in dollars is 1.54

the tax % will be   (amount of tax / original cost price ) × 100

(1.54 / 22) × 100  → (0.07) × 100 =   7

so the tax rate is 7%

we can double check the answer.

7 % of 22   → (7/100) × 22 → 0.07 × 22 = 1.54

22 + 1.54 = 23.54"