harpazo Pure Mathematics Aug 28, 2018 #1 If 3/7 of students wear backpacks and 2/5 of students are not in full school uniform, find the probability that a student is wearing a backpack and is in full school uniform.

If 3/7 of students wear backpacks and 2/5 of students are not in full school uniform, find the probability that a student is wearing a backpack and is in full school uniform.

MarkFL La Villa Strangiato Math Helper Sep 22, 2018 #2 \(\displaystyle P(X)=\frac{3}{7}\left(1-\frac{2}{5}\right)=\frac{9}{35}\)

Jason Well-known member Mar 31, 2020 #4 The thing to spot here - is the fact that the ones without school uniforms are the only other group - and they obviously - don't have backpacks!

The thing to spot here - is the fact that the ones without school uniforms are the only other group - and they obviously - don't have backpacks!