Question 277125
A silversmith mixed 40 g of a 70% silver alloy with 75 g of a 15% silver alloy.
 What is the percent concentration of the resulting alloy?
 (Round your answer to the nearest tenth of a percent.)
:
Let x = percent of resulting alloy
70(40) + 15(75) = x(75+40)
2800 + 1125 = 115x
3925 = 115x
x = {{{3925/115}}}
x = 34.1 %