Answer:
9 white ribbons were awarded
Step-by-step explanation:
make white x
make blue b and make red r
b=x-1
r=x+3
w=x
add them up
x-1+x+3+x=29
x-1 +x+3 is 2x+2
2x+2+x=29
3x+2=29
subtract 2 on both sides
3x=27
divide by 2
x=9
