Gmat_mission wrote:On a Monday in a certain restaurant, 20 percent of the 180 customers ordered the daily special. On Tuesday, only 10 percent of the 120 customers ordered the special. For the two days combined, what percent of the customers ordered the daily special?
A. 15%
B. 16%
C. 18%
D. 23%
E. 30%
[spoiler]OA=B[/spoiler].
How should I solve this PS question? What are the formulas that I should use? Thanks.
Hello Gmat_mission.
On a Monday in a certain restaurant, 20 percent of the 180 customers ordered the daily special, that is to say, 20%*180 = 36 customers.
On Tuesday, only 10 percent of the 120 customers ordered the special, that is to say, 10%*120 = 12 customers.
The total number of customers (Monday and Tuesday) is: 180 + 120 = 300.
The total number of customers that ordered the daily special (Monday and Tuesday) is: 36 + 12 = 48.
Now, if 300 customers is the 100%, then 48 customers represents the $$x=\frac{48\cdot100}{300}\%=\frac{4800}{300}\%=16\%.$$ Hence, the correct answer is
B.
I hope it helps.