Problema Solution

There were 55 dancers at the Jazz & Samba Studio. When 7 jazz dancers dropped out of dancing classes altogether and 12 samba dancers moved to jazz classes, then the number of samba dancers became a third of the number of the jazz dancers. At the beginning, how many of the 55 dancers were in jazz classes?

Answer provided by our tutors

jazz +samba=55

now {(j-7)+12}/3+(s-12)=55-7

(j-5)/3+s-12=48

(j-5)/3+55-j-12=48

j-5/3-j=43

so j=67 

hence in beginning there were 48 jazz dancers