Q) how much salt must be added to 60 litres of a 20% solution of salt to increase it to a 40% 
    solution of salt

Asked by gn | 2nd Nov, 2016, 08:24: PM

Expert Answer:

begin mathsize 16px style In space 60 space litres comma space amount space of space salt space is space 20 percent sign space of space 60 space equals space 20 over 100 cross times 60 equals 12
Let space the space amount space of space salt space to space be space added space be space straight x space to space increase space the space solution space of space straight a space 40 percent sign space solution space of space salt.
So comma space the space amount space of space salt space in space straight a space 40 percent sign space solution space is space straight x plus 12.
rightwards double arrow straight x plus 12 space equals 40 over 100 cross times 60
rightwards double arrow straight x plus 12 space equals space 24
rightwards double arrow straight x equals 12
Hence comma space the space amount space of space salt space to space be space added space is space 12. end style

Answered by Rebecca Fernandes | 3rd Nov, 2016, 08:14: AM