Question 937607
A chemist has a solution that is 50 percent acid.-----------x cc  50%


 By adding water, ...................y cc 0% acid

the solution is reduced to one containing 40 percent acid.40%(x+y)

50%x+0%y = 40%(x+y)

multiply by 100
50x= 40(x+y)

50x=40x+40y
10x= 40 y

y=1/4 x

The total solution now is (x+x/4) = 5x/4.............40%

40%*5x/4+500cc water*0% acid = 35%(5x/4 + 500)

multiply by 100
50x + 0 = (35(5x+2000)/4))

200x = 175x+70000

25x= 70000
x= 70000/25

x= 2800 cc

Check

2800*50%+3500*0 = z%(3500)

z=20%


Total solution = (5x/4  +500)

plug x

(5*2800/4 +500)

3500+500=4000 cc of final solution





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