Question 972880
The number of possible combinations of n people taken r at a time is:
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{{{n!/(r!(n-r)!)}}}
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For  students on committee:n=6; r=4
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{{{6!/(4!(6-4)!)=6*5/(2*1)}}}={{{30/2=15}}} possible groups of students.
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For teachers on committee: n=5; r=3
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{{{5!/(3!(5-3)!)=5*4/(2*1)}}}={{{20/2=10}}} possible groups of teachers.
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There are 15 different groupings of students and 10 different groupings of teachers, so total there are (15)*(10)=150 different committees possible