The proportion of copper and zinc in the brass is 3:7. How much zinc will there be in 100 kg of brass?	Select the correct option:	A) 70	B) 50	C) 40	D) 270	E) 170
7/10 * 100= 
<gadget id="calculator">7/10 * 100</gadget>
<output>70</output>
70   70NSWER:70
<result>A</result>
The proportion of copper and zinc in the brass is 3:7. How much zinc will there be in 100 kg of brass?