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secondary 4 | E Maths
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Royal Lim
Royal Lim

secondary 4 chevron_right E Maths chevron_right Singapore

I am confused by the words?how to do?TIA

Date Posted: 4 years ago
Views: 376
J
J
4 years ago
P(chosen at least once)

= P(chosen only once) + P(chosen twice)

= P(first name is Nicholas, but not the second)
+ P(second name is Nicholas, but not the first)
+ P(both names are Nicholas)

= (1/10 x 9/10) + (9/10 x 1/10) + (1/10 x 1/10)

= 9/100 + 9/100 + 1/100
= 19/100
J
J
4 years ago
Complement method :

P(Nicholas is chosen at least once)

= 1 - P(Nicholas is not chosen at all)

= 1 - (both first and second names are not Nicholas)

= 1 - (9/10 x 9/10)

= 1 - 81/100

= 19/100
Eric Nicholas K
Eric Nicholas K
4 years ago
The question, if you observe carefully, is similar to

"Ten balls are placed in a container. One of the balls is red. Two balls are drawn with replacement."
J
J
4 years ago
Yes same concept. Royal, please learn to identify similar questions and apply the same strategy. You'll need to draw parallels across different questions

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Arnold K H Tan
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