In 5 years joyce will be twice as old as mensah (im pretty sure
Try, please, this:
1) Imagine, that pharmacist used 'x' gr. of 40% solution and 'y' of 70% solution.
Together (20 gr. of 52% sol.) it will be x+y=20.
2) From other side, the pharmacist combined 40x and 70y gramms, after obtaining together it is 52(x+y) gramms. In other words 40x+70y=52(x+y)
3)

Answer: 8 gr. of 70% solution and 12 gr. of 40%.
Answer = $39.78
100-20 =80
100-25=75
Multiply 60 x .80 to get $48
Then multiply 48 x .75 to get $36
Sales tax %10.5 = move decimal two places to left .105
Now multiply 36 x .105 =3.78
$3.78 equals your sales tax
Finally add $3.78+$36= $39.78
Coonnecting Rod is the answer