Terrell went on a vacation and bought 2 postcards each day
This implies that he bought 2 postcards everday
He spent a total of 9 days
Total post card = No of days spent x number of postcards bought each day
Number of days = 9
Number of postcards =2
Total number of postcards = 9 x 2
Total number of postcards = 18
The answer is 18 postcards