if, value cell formula

I want to be able to sum a value of 1.42587 for of all cells (b3:h12) that contain the letter "y" and the total needs to be displayed in cell g12. if a cell contains "n" then a value of 0.

this is for a simple table for the kids doing chores/ homework. the table shows each chore on the side and days of the week on top. if the kid did whatever is represented in the cell on that day, he types in a "y" and a sum is added to the weekly total.