If you subtract 0.3 from a certain number then add 0.4 of the original number, then another 2.78, you'll get 25. what was the original number?

Assume that the number we are looking for is x.

We are given that:

1 - subtract 0.3 from the number

The expression becomes: x - 0.3

2 - add 0.4 of the original number

The expression becomes: x-0.3+0.4x

3 - add another 2.78

The expression now becomes: x-0.3+0.4x+2.78

4 - the result is 25

Theredore, the final expression is:

x-0.3+0.4x+2.78 = 25

Solve this expression for x as follows:

x-0.3+0.4x+2.78 = 25

1.4x + 2.48 = 25

1.4x = 25-2.48

1.4x = 22.52

x = 22.52/1.4

x = 16.0857