3. Buying 2 bottles of soda and 1 bottle of mineral water costs 7 yuan, buying 4 bottles of soda and 3 bottles of mineral water costs 16 yuan, then buying 10 bottles of soda and 10 bottles of mineral water will cost $\qquad$ yuan.
(A) 45
(B) 46
(C) 47
(D) 55
【Answer】A
【Analysis】Subtracting the two conditions, we find that 2 bottles of soda and 2 bottles of mineral water cost 9 yuan, so 10 bottles of soda and 10 bottles of mineral water would cost 5 times 9 yuan, which is 45 yuan.