Question 1046787
Let x be the amount of the 10% solution
MIX:
.50(60) + .10x = .25(60+x)
Solve
.50(60) + .10x = .25(60) + .25x
.25(60) = .15x
.25(60)/.15 = x,  the amount of the 10% solution (100cc)

AND
30 + 10 = .25(160)  CHECKS!