tal weight of all 100 beads is 200 grams.find how many beads there are of each color

Question

you have 100 beads .Some are red, some are blue and sone are white And they weigh respectively, 20 grams, 6 grams, and 1 gram. The total weight of all 100 beads is 200 grams. Find how many beads there are of each color.

 

Answer 1

20R+6B+1W=200

R+B+W=100

W=100-R-B

substitute into the first equation

20R+6B+100-R-B=200

19R+5B+100=200

19R+5B=200-100

19R+5B=100

by observation, R=5 and B=1  (19*5+5*1=100)

therefore 5+1+W=100

6+W=100

W=100-6

W=94

there are 5 RED, 1 BLUE, and 94 WHITE

5*20+1*6+94*1=100+6+94=200