Answer:
o calculate the percentage of computers with the Microsoft operating system installed, we need to find the total number of computers that have either Windows XP or Windows 7 installed.
Microsoft Windows XP operating system is installed on 20% of the company's computers, so 20% of the computers have Windows XP installed.
Microsoft Windows 7 is installed on 85% of computers, so 85% of the computers have Windows 7 installed.
Linux and Microsoft Windows 7 are installed on 6% of computers, so 6% of the computers have both Windows 7 and Linux installed.
Microsoft Windows XP and Linux on 4% of computers, so 4% of the computers have both Windows XP and Linux installed.
All three programs are installed on 2% of computers, so 2% of the computers have all three programs installed.
To avoid double-counting the computers that have both Windows 7 and Linux installed, we need to subtract 6% from the total number of computers with Windows 7 installed. The same applies to the computers that have both Windows XP and Linux installed, so we need to subtract 4% from the total number of computers with Windows XP installed.
The total number of computers with Windows XP or Windows 7 installed is 20% + (85% - 6%) + (20% - 4%) = 20% + 79% + 16% = 115%.
So, 115% of the company's computers have the Microsoft operating system installed.
Explanation: