Answer:
- <em>0.75</em><em> liters of 5% hydrochloric acid solution </em>
- <em>0.25</em><em> liters of 45% hydrochloric acid solution.</em>
Step-by-step explanation:
Let us assume that, x liters of the 5% hydrochloric acid and y liters of the 45% hydrochloric acid solutions are combined.
As Rajan need total of 1 liter of solution, so
 
 
i.e  --------------------1
 --------------------1
As Rajan needs 5% hydrochloric acid and 45% hydrochloric acid to make a 1 liter batch of 15% hydrochloric acid, hence acid content of the mixture of two acids will be same as of the final one, so

i.e  -------------2
 -------------2
Putting value of x from equation 1 in equation 2,





Putting the value of y in equation 1,

Therefore, Rajan must use 0.75 liters of 5% hydrochloric acid solution and 0.25 liters  of 45% hydrochloric acid solution.
 
        
             
        
        
        
3(x-1) = 2x - y
3x-3 = 2x-y
3x-2x+y = 3
x + y = 3 ----> (1)
2(x+y) = 3+3y
2x + 2y = 3 + 3y
2x + 2y - 3y = 3
2x - y = 3 -----> (2)
make equation (1) and (2) together 
x + y + 2x - y = 3+3
3x = 6
x = 2
now make x = 2 in equation (1)
x + y = 3
2 + y = 3
y = 3-2
y = 1
(x,y) = (2,1)
        
             
        
        
        
And what else is in the problem I do not get what the problem is
        
             
        
        
        
Answer:
2/3
Step-by-step explanation:
2/15 of 5
Of means multiply
2/15 * 5
Multiply the numerators
2*5 = 10
Put over the denominator
10/15
We can divide the top and bottom by 5
10/5 =2
15/5 =3
2/3