Answer:
The cost of Tammy lunch is 9.6 unit .
Explanation:
Given as :
The percentage of sales tax = 7.5 %
The tax amount on cost = 0.72
Let the cost of Tammys lunch = x unit
So,
∵ The sales tax is applied on the cost
∴ 7.5 % of x = 0.72
Or, 0.075 × x = 0.72
Or, x =

∴ x = 9.6 unit
Hence The cost of Tammy lunch is 9.6 unit . Answer