Patel and Sons Inc. uses a standard cost system to apply factory overhead costs to units produced. Practical capacity for the plant is defined as $53,700$ machine hours per year, which represents $26,850$ units of output. Annual budgeted fixed factory overhead costs are $$268,500$ and the budgeted variable factory overhead cost rate is $$3\mathrm{.}20$ per unit. Factory overhead costs are applied on the basis of standard machine hours allowed for units produced. Budgeted and actual output for the year was $20,700$ units, which took $42,700$ machine hours. Actual fixed factory overhead costs for the year amounted to $$259,300$ while the actual variable overhead cost per unit was $$3\mathrm{.}10.$

Based on the information provided above, what was $($a$)$ the variable overhead spending variance for the year, and $($b$)$ the variable overhead efficiency variance for the year? Indicate whether each variance was favorable $($F$)$ or unfavorable $($U$).$