Question

1 kg Alloy has 40% tin and 60 copper. How much tin should be mixed in it and the ratio of tin and copper to 60: 40.

Answer 1

40...........
40/ 100×100
40

Answer 2

HERE IS YOUR ANSWER:
There is 1000 gram of alloy out of which 400 g is tin and 600 g is copper. So, if you add x to tin total alloy will be 1000+x.
After this the ratio of tin÷total alloy= 60%.

let tin to be mixed be x.

Now,
$(400 + x )\div( 1000 + x) = 60 \div 100$
Solving it, we get x=500grams
After adding 500g to 400g tin
Tin=900g and copper= 600g and hence ratio 60:40.

Hence, 500 g of tin should be added to make ratio as 60:40