First, Accounting CS takes 100% of the 401(k) deduction ($70) with a limit of up to 2% of gross pay (1000 x .02 = $20) and it calculates $20 for that portion.
The next limit is $60 (1000 x .06 = $60), but we already matched $20, so $40 are left. The 2nd tier matches half of this, so the match is another $20.
The final limit is $100 (1000 x .1 = $100), and with the already matched amounts, we're left with $40 maximum to match ($100 - $20 from the first tier - $40 from the 2nd tier = $40). However, this exceeds the employee deduction limit of $70, so the match amount is reduced to $30. 25% of the remaining $30 is $7.50.
The employer match is $47.50 ($20 from 1st tier + $20 from 2nd tier + $7.50 from the 3rd tier).