A basket contains some white, red and black balls. There are 15 white and red balls. There are 18 red and black balls. The number of black and white balls is 9. Find the number of balls for each colour.
+318 https://www.jiskha.com/questions/1854755/a-basket-contains-some-white-red-and-black-ball-there-are-15-white-and-red-balls-there
answer is there
+1639 A basket contains some white, red, and black balls. There are 15 white and red balls. There are 18 red and black balls. The number of black and white balls is 9. Find the number of balls for each color.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
w + r = 15 w = 15 - r 15 - r + 18 - r = 9 r = 12
b + r = 18 b = 18 - r
w + b = 9
w = 3 r = 12 b = 6
