Question

Which one of the following must be false?

• A. Exactly five mobile phones feature a music player
• B. Exactly five mobile phones feature a document viewer
• C. Exactly four mobile phones feature a music player.
• D. Exactly four mobile phones feature a digital camera.

Answer 1

The correct option is A Exactly five mobile phones feature a music player

$\begin{array}{cccc}MobileModels& DigitalCamera& MusicPlayer& OfficeDocumentViewer\\ T& & & \\ V& ✓& & ✓\\ W& ✓& ✓& ✓\\ X& ✓& ✓& ✓\\ Y& & & ✓\\ Z& & ✓& \end{array}$
The options for 4 models are clear. Further Z has a music player as T has fewer options as compared to Z, i.e., Z has 2 options as T will have 1 option. So one option has to be music player for Z as only one option is common with V who has digital camera and office Document viewer. The one option T has can be a music player so only a maximum of 4 mobiles have a feature of music player.