There is a collection of stamps where 68% are foreign stamps, 45% are issued more than 10 years ago and 30% are foreign stamps issued over 10 year ago.

There are 1200 stamps in total.

How many foreign stamps issued within 10 years?

My solution is (look at the image below):

Attachment 19830

68% of 1200 = 816 which is the total number of Foreign stamps

45% of 1200 = 540 which is the total of 10+ stamps. Therefore 660 are total of foreign stamps issued 10- years.

30% of 660 = 198 which is the foreign stamps issued 10- years.

The answer is : 198

Thank you in advance