please help! All questions are needed :)

Use the following data for questions 13 thru 17: XYZ Engineering performs cement core tests in its laboratory. The following standards have been set for each core test performed: During March, the laboratory performed 2,000 core tests. On March 1 no direct materials (sand) were on hand. Variable manufacturing overhead is assigned to core tests on the basis of standard direct labor-hours. The following events occurred during March: - 7,200 pounds of sand were purchased at a cost of $6,120. - 7,200 pounds of sand were used for core tests. - 840 actual direct labor-hours were worked at a cost of $8,610. - Actual variable manufacturing overhead incurred was $7,240. The materials price variance for March is: $720 unfavorable $720 favorable $281 unfavorable $281 favorable The materials quantity variance for March is $900 favorable $1,950 favorable $1,950 unfavorable $900 unfavorable Question 15 The labor rate variance for March is: $4,578 unfavorable $1,470 unfavorable $4,578 favorable $1,470 favorable