Aworker's salary was reduced by 60%. by what percent must the new salary be raised to bring it back to the original amount

Let the original salary be x, then the new saraly is (100 - 60)/100 x = 0.4x
To get back the original amount ,we find what must be multiplied to 0.4 to give 1.
Let the number that will be multiplied to 0.4 to give 1 be y, then
0.4y = 1
y = 1/0.4 = 2.5 = = 1 + 1.5 = 150%

Therefore, the new saraly must be raised by 150% to bring it back t the original amount.