The strength of a salt solution is p% if 100 ml of the solution contains p grams of salt. Each of three vessels A, B, C contains 500 ml of salt solution of strengths 10%, 22%, and 32%, respectively. Now, 100 ml of the solution in vessel A is transferred to vessel B. Then, 100 ml of the solution in vessel B is transferred to vessel C. Finally, 100 ml of the solution in vessel C is transferred to vessel A. The strength, in percentage, of the resulting solution in vessel A is

Initially, vessels A, B, and C each contain 500 ml of solution at concentrations 10%, 22%, and 32% respectively.

Step 1: 100 ml of A is transferred to B.
The volume transferred from A is 100 ml at 10% strength, containing 10 grams of salt.
Vessel A is left with 400 ml of solution at 10% strength (containing 40 grams of salt).
Vessel B now has 500 ml + 100 ml = 600 ml of solution.
The total salt in B is:
$500\times 0.22+10=110+10=120\text{grams}$
The new concentration of B is:
$\frac{120}{600}\times 100\%=20\%$

Step 2: 100 ml of B is transferred to C.
The volume transferred from B is 100 ml at 20% strength, containing 20 grams of salt.
Vessel B is left with 500 ml of solution at 20% strength.
Vessel C now has 500 ml + 100 ml = 600 ml of solution.
The total salt in C is:
$500\times 0.32+20=160+20=180\text{grams}$
The new concentration of C is:
$\frac{180}{600}\times 100\%=30\%$

Step 3: 100 ml of C is transferred to A.
The volume transferred from C is 100 ml at 30% strength, containing 30 grams of salt.
Vessel A (which had 400 ml of 10% strength solution, containing 40 grams of salt) now receives this 100 ml of 30% solution.
The final volume of A is 500 ml.
The total salt in A is:
$40+30=70\text{grams}$
The final concentration of A is:
$\frac{70}{500}\times 100\%=14\%$