Answer:
boys = 150
girls = 350
Step-by-step explanation:
I'm not sure what a tape diagram is, but I can get the answer.
Let b = boys
Let g = girls
3/7 = b/g
3/7 = b/(b + 200)
3(b + 200) = 7b
3b + 600 = 7b
600 = 4b
b = 600/4
b = 150
g= 150 + 200
g = 350
