Initial amount of salt in vessel A = 10 gms per 100 ml. solution. Therefore in 500 ml solution in vessel amount of salt = 50 gms
Similarly, initially in 500 ml solution in vessel B amount of salt = 110 gms
and initially in 500 ml solution in vessel C, amount of salt = 160 gms
When 100 ml is transferred from A to B, the amount of salt now in B = 10 + 110 = 120 gms in 600 ml.
The new concentration of salt in B = 120 / 600 x 100
= 20 gms per 100 ml.
Now, the amount of salt in A = 50 – 10 = 40 gms in 400 ml
Now, when 100 ml is transfered from B to C, the amount of salt now in C = 20 + 160 = 180 gms in 600 ml.
The new concentration of salt C = 180 / 600 x 100
= 30 gms per 100 ml
Finally, when 100 ml is transfered from C to A, the amount of salt now in A = 30 + 40 = 70 gms in 500 ml.
∴ Strength of salt in 70 / 500 x 100 = 14