sol contain D5W another one contain D50W we want to prepare sol cotain D15W its volune is 450ml
- how much ml we need of each sol
 - 5% ------ 35
 - 15%
 - 50% -----10
 
Steps to calculate the volume of each solution:
Sure, here are the steps to calculate the volume of each solution needed to prepare a solution of D15W with a volume of 450 ml:
- Let x be the volume of D5W needed and y be the volume of D50W needed.
 - We know that the total volume of the solution is 450 ml, so we can write the equation: x + y = 450
 - We also know that the concentration of D15W is 15%, which means that 15% of the total volume of the solution is D15W. We can write this equation: 0.15(x + y) = 67.5
 - Now we have two equations with two unknowns, and we can solve for x and y. We can solve the first equation for x: x = 450 - y
 - We can substitute this expression for x into the second equation: 0.15(450 - y) + y = 67.5
 - Simplifying this equation, we get: 67.5 - 0.15y + y = 67.5
 - Solving for y, we get: y = 200
 - Now we can substitute this value of y back into the equation x = 450 - y to find x: x = 450 - 200 = 250
 - Therefore, we need 250 ml of D5W and 200 ml of D50W to prepare a solution of D15W with a volume of 450 ml.