







How many students have neither brown hair or hazel eyes? 
20130120 

From Julie: There are 28 students in a class. 15 have brown hair, 17 have hazel eyes, and 10 have both. How many students have neither brown hair or hazel eyes? Answered by Penny Nom. 





Conditional probability 
20100326 

From Sandy: In a certain school, it is known that 80% of the students use the internet for school projects, 60% use email on a regular basis, and 90% use the internet for school projects or for email on a regular basis. A student from this school is selected at random
Determine the probability that the student used email, given that the student used the internet for school projects.
Sandy Answered by Penny Nom. 





All wiffs are miffs and all miffs are kiffs. 
20080608 

From Allison: All wiffs are miffs. all miffs are kiffs. There are 25 wiffs. There are 76 kiffs. 33 kiffs are not miffs. How many miffs are not wiffs? Answered by Penny Nom. 





A health club 
20011125 

From Maria: A health club with a membership of 650 people operates a running track and an indoor swimming pool. A survey of the membership indicates that 68% use the running track, 44% use the swimming pool, and 8% use neither. If a member is chosen at random, what is the prbability that the member uses: a) Both the track and the pool? b) Only the track? Answered by Penny Nom. 





Derfs, Enajs and Sivads 
20010107 

From John and Norman: All Derfs are Enajs. Onethird of all Enajs are Derfs. Half of all Sivads are Enajs. One Sivad is a Derf. Eight Sivads are Enajs. The number of Enajs is 90. How many Enajs are neither Derf nor Sivad? Answered by Penny Nom. 





100% on two tests 
20000201 

From Craig and Chelsea Bruzzone: A class of 35 students took a math test and a science test. 12 students got 100% on the math test. 9 students got 100% on the science test. There were 19 students who made less than 100% on both tests. How many students made 100% on both tests? Answered by Penny Nom. 

