Total=110=D+J+K
D=(2/3)J
K=2J
...a...
If J=x,
D=(2/3)x ⟨— i
K=2x ⟨— ii
...b...
T=D+J+K
110=(2/3)x+x+2x ⟨— b
...c...
110=2x/3+3x/3+6x/3
110=11x/3
330=11x
330/11=x
30=x
D=(2/3)x
D=(2/3)(30)
D=20
Dennis received 20 marbles ⟨— c
