Crystal Fabrication allocates manufacturing overhead using a single predetermined rate based on a planned use of $12,000$ direct labour hours per year. Company leadership recently learned that its costing system may be too simple for its operations, and that job costs may be fairly inaccurate. A consultant was hired to study overhead costs, and the following information reflects the cost pools and activity rates that were determined:

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Based on the information presented in the introduction and table above, Crystal Fabrication$$s single predetermined manufacturing overhead cost rate is $\_\_\_\_\_\_$

a$.$

$$15/$direct labour hour

b$.$

$$30/$direct labour hour

c$.$

$$24/$direct labour hour

d$.$

$$60/$direct labour hour $\backslash$begin$\{$tabular$\}\{|$c$|$c$|$c$|\}$

$\backslash$hline Cost Pool & Total Cost & Activity Rate $\backslash \backslash$

$\backslash$hline Purchasing & $\backslash$$$60,000$ & $\backslash$$$48/$purchase order $\backslash \backslash$

$\backslash$hline $\backslash$begin$\{$tabular$\}\{$l$\}$

Machine $\backslash \backslash$

Setups

$\backslash$end$\{$tabular$\}$ & $\backslash$$$40,000$ & $\backslash$$$80/$setup $\backslash \backslash$

$\backslash$hline Assembly & $\backslash$$$180,000$ & $\backslash$$$15/$direct labour hour $\backslash \backslash$

$\backslash$hline Inspections & $\backslash$$$80,000$ & $\backslash$$$20/$inspection $\backslash \backslash$

$\backslash$hline Total & $\backslash$$$360,000$ & $\backslash \backslash$

$\backslash$hline

$\backslash$end$\{$tabular$\}$