Answer:
19 red beads
Step-by-step explanation:
We first need to find a common denominator of 4/9, 1/5 and 1/4.
The common denominator is 180. Like in an expression, what we do to one side we have to do to the other.
Silver - 180/9 = 20 ; 20*4 = 80 so there are roughly 80 sliver beads.
Gold - 180/5 = 36 ; 36*1 = 36 so there are roughly 36 gold beads.
Blue - 180/4 = 45 ; 45*1 = 45 so there are roughly 56 blue beads.
180 - (silver+gold+blue) = red beads
180-161 = 19 red beads b/c ----->
80+36+45+19 = 180
