|
man u need to know the basics (no offense) . por favor, El Seņor refer to nova book for gre.. some good cocepts there..
2)total is 42
jelly can be choc, white, or dark -->> 3
caramel can be choc(plain), choc (nuts), dark(plain) , dark(nuts), white(plain), white(nuts) -->> 6
similarly for fudge -->> 6
similarly for cream -->> 6
add them u get 21 . now they are equally distributed so if u double all the no. u get 42 sweets...
now with jelly is 6 and without are 36 so 36/6=6
But this is for explanation only u need to be quick in combinations.. like
(if there are 3 ways a,b,c and again 3 ways e,f,g so effectively there r 9 ways 3x3 ae,af,ag,be,bf,bg,ce,cf,cg.. same concept here)
jelly -->1x3 (3 is the no. of coatings, 1 is for jelly only)
others (becoz they r similar) --> 3x3x2 =18 (3 is for three centers, then 3 is for coatings, and 2 is for plain or nuts)
so the odds r 18/3 (jelly/nonjelly) = 6
to make the total 42 u may multiply both numerator and denominator by 2 but the odds remain unchanged
I hope u understood
best of luck
|