The ratio of copper and zinc in a brass alloy is 13 : 7. How much zinc will be there in 100 kg of the alloy?

Gold is 19 times as heavy as water and copper is 9 times as heavy as water. In what ratio should these be mixed to get an alloy 15 times as heavy as water?

The ratio of copper and zinc in an alloy is 5 : 4. If 1.25 kg of zinc is added to 11.25 kg of this alloy, find the new ratio of copper to zinc.

Two alloys contain tin and iron in the ratio 1:2 and 2:3. If the two alloys are mixed in the proportion of 3:4 by weight, the ratio of tin and iron in the newly formed alloy is:

Two alloys contain zinc and copper in the ratios 2:3 and 4:1. In what ratio should these two alloys be mixed to form a new alloy containing zinc and copper in the ratio 1:1?

The ratio of copper and zinc in an alloy is 5 : 2. If 1.5 kg of zinc is added to 17.5 kg of the alloy, find the new ratio of copper and zinc.

The ratio of copper and zinc in an alloy is 9 : 4. If there is 24 kg of copper, find the weight of zinc in the alloy.