Correct Answer: Option B

Explanation

n(Total) = 50

n(Physics) = 40

n(Biology) = 30

Let n(Physics and Biology) = x

n(Physics only) = 40 -x

n(Biology only) = 30 - x

40 - x + 30 - x + x = 50

70 - x = 50

x = 20

There is an explanation video available below.

• Socio economic impact of the mass emigration (japa) on the Nigerian economy? Answer this

  1 Answers   ·   English Language   ·   4 hours ago
• Pls is it too late to register for ond?? Answer this

  0 Answers   ·   5 hours ago
• explain broadly what methods of political enquires is all about? Answer this

  1 Answers   ·   Social Science   ·   12 hours ago