Here are the answers, however I am confused as to how the $25 on part (a) got there, could anyone please explain that to me. Thanks

Question 2 Qinthara Ltd manufactures kitchen products at its Naperville plant. Unfortunately, during the recent floods, part of the company's accounting records was destroyed. The company accountant has been able to gather the following data from the waterlogged files Direct Labour Standard hours per unit of output Standard direct labour rate per hour 4 hours Actual hours used per unit of output S23 per hour Actual rate per unit of input 10,000 units Actual output Direct labour rate variance $125,000 U Direct labour efficiency variance 45,000 U Total of direct labour variances Required: Compute the missing elements in the report represented by the lettered items (a-c)