$13.$ The following materials standards have been established for a particular product:

Standard quantity per unit of output $4\mathrm{.}6$ grams

Standard price $ $15\mathrm{.}05$ per gram

The following data pertain to operations concerning the product for the last month:

Actual materials purchased $3,100$ grams

Actual cost of materials purchased $ $44,020$

Actual materials used in production $2,400$ grams

Actual output $300$ units

What is the materials quantity variance for the month?

A$)$ $$9,940$ U

B$)$ $$15,351$ U

C$)$ $$14,484$ U

D$)$ $$10,535$ U

$14.$ refer to the data in question $13.$ What was the Material Price Variance?

A$)$ $$2,635$ F

B$)$ $$7,900$ U

C$)$ $$7,900$ F

D$)$ $$2,635$ U

What is the math beind $7900$U$?$