A small store made 50 posters to advertise their products. Two-fifths of them are small posters while half of them are medium posters. The rest are large posters. How many large posters are there?
Think hard. Detailed solution:
5
50 x 2 / 5 = 20 posters are small.

And 50 / 2 = 25 posters are medium.

So 20 + 25 = 45 posters are not large.

Therefore, 50 - 45 = 5 posters are large.

.

The final answer: 5