math
posted by swagnik .
The ratio of zinc and copper in an alloy is 7:9. if the weight of copper in the alloy is 11.7 kg, find the weight of zinc in alloy?

zinc : copper = 7:9
zinc/11.7 = 7/9
zinc = 11.7(7/9) = .... 
11.7 × 7/9
=9.1 kg