Sam College allocates support department costs to its individual schools using the step$-$down method. Information for May $2003$ follows:

Support Departments

Maintenance Power

Cost incurred $$99,000$ $$54,000$

Service percentages provided to:

Maintenance $----10\%$

Power $20\%----$

School of Education $30\%20\%$

School of Technology $50\%70\%$

$100\%100\%$

What is the amount of May $2003$ support department costs allocated to the School of Education?

$$40,500$

$$42,120$

$$46,100$

$$49,125$ I need help with an explanation. Thanks!