Four more than three-fifths of a number is thirteen what number is it

Hello from MrBillDoesMath!

15

Discussion.

Call the number referred to "n".  Then the problem statement becomes:

4 + (3/5) * n = 13

Multiply both sides of the equation by 5 :

5 ( 4 + (3/5)*n) = 13 * 5  or

5*4 + 5 * (3/5)**n = 13*5

Cancelling the boldfaced 5's gives:

5*4 + 3*n = 13 *5  or

20 + 3*n = 65

Subtracting 20 from both sides gives:

3*n = 65-20 - 45

Dividing by 3 gives n = 15

Check: 4 + (3/5)*15 =  4 + 9 = 13!   Bingo

Regards, MrB