Highfill Corporation's variable overhead is applied on the basis of direct labor$-$hours. The standard cost card for product D$80$D specifies $6\mathrm{.}7$ direct labor$-$hours per unit of D$80$D$.$ The standard variable overhead rate is $$7\mathrm{.}00$ per direct labor$-$hour. During the most recent month, $1,100$ units of product D$80$D were made and $7,500$ direct labor$-$hours were worked.

The actual variable overhead incurred was $$57,390.$

Required:

a$.$ What was the variable overhead spending variance for the month?

b$.$ What was the variable overhead efficiency variance for the month?

$($Indicate the effect of each variance by selecting $"$F$"$ for favorable, $"$U$"$ for unfavorable, and "None" for no effect $($i$.$e$.,$ zero variance$).$ Input all amounts as positive values.$)$