thanks for the tip . I 've done it below

v1+v2 =10

v1*50/100+v2*25/100=10*40/100

2v1+v2=1

:. v1=6 &v2=4

ie6litres of 50% acid solution and 4 litres of 25% acid solutions are to be mixed.

i hope this is the answer.

thanks for the tip . I 've done it below

v1+v2 =10

v1*50/100+v2*25/100=10*40/100

2v1+v2=1

:. v1=6 &v2=4

ie6litres of 50% acid solution and 4 litres of 25% acid solutions are to be mixed.

i hope this is the answer.