At the beginning of the year, MB Company had the following standard cost sheet for one of its plastic products. MB planned to produce $4,000$ units for the year.

Direct materials $(4$ pounds at $$2\mathrm{.}50$ per pound$)$ $$10\mathrm{.}00$

Direct labor $(3$ hours at $$20$ per hour$)60\mathrm{.}00$

Standard prime cost per unit $$70\mathrm{.}00$

MB uses a standard costing system.

During the year, a variable overhead rate of $$3\mathrm{.}75$ per direct labor hour was used.

Actual results:

Actual number of units produced: $4,200$

Materials purchased: $18,000$ pounds at $$2\mathrm{.}65$ per pound

Materials used in production: $16,700$ pounds

Direct labor: $12,000$ hours at $$21$

Actual variable overhead: $$42,000$

Compute the following variances. Remember to label your answers with an F or U$.$

$1.$ Variable overhead spending variance

$2.$ Variable overhead efficiency variance