Question

2. An alloy A contains two elements, copper
and tin in the ratio of 2:3, whereas an alloy
B contains the same elements in the ratio of
3:4. If 20kg of alloy A, 28kg of alloy B
and some more pure copper are mixed to
form a third alloy C which now contains
copper and tin in the ratio of 6 : 7, then
what is the quantity of pure copper mixed
in the alloy C??​

Answer 1

Answer:

I think the answer is 7:9..........