Carson Construction Consultants performs cement core tests in its Greenville laboratory. The following standard costs for the tests have been developed by the companys controller, Landon Carson, based on performing 2,100 core tests per month. Standard Price Standard Quantity Standard Cost Direct materials $0.50 per pound 4 pounds $2.00 Direct labor $10 per DLH .5 DLH 5.00 Variable overhead $9 per DLH .5 DLH 4.50 Fixed overhead $16 per DLH .5 DLH 8.00 Total standard cost per test $19.50 At the end of March, London reported the following operational results: The company actually performed 2,250 core tests during the month. 8,500 pounds of direct materials were purchased during the month at a total cost of $5,600. 6,300 pounds of direct materials were used to conduct the core tests. 850 direct labor hours were worked at a total cost of $9,775. Actual variable overhead was $7,800. Actual fixed overhead was $15,750.

Prepare a memo to Landon Carson providing possible explanations for the direct materials and direct labor variances.