Given :
Volume , V = 500 mL .
Molarity , M = 0.5 M .
Molecular mass of NaCl is 
.
To Find :
How many grams of NaCl is required .
Solution :
Let , NaCl required is x gram .
Molarity is given by :
Hence , this is the required solution.
So let's use some equations to represent the data [let R= cost of ring & B= cost of bracelet]
R= B + $ 36 .... (1)
B=
× R ... (2)
By using simultaneous equations to solve for B and R.
Substitute eq. (1) into eq. (2)
B =
× (B + $36)
B =
B +
⇒ B = $48
By substituting value of B into ea (1)
If R = B + $36
R = ($48) + $36
= $84
∴ <span> the total of the two items = R + B
= $84 + $48
</span> = $132
