4. Anna, Beate and Cindy buy a bag of 30 biscuits together. They get 10 biscuits each. But Anna has paid 80 cents, Beate 50 cent
s and Cindy 20 cents. How many more biscuits should Anna have got, if they had shared them in proportion with the amount they had each paid? (A) 10 (B)9 (C) 8 (D) 7 (E) 6