Which of the following could possibly explain both an unfavorable direct materials quantity variance and a favorable direct materials price variance occurring during the same period?

a. The purchase of lower-quality direct materials

b. The use of inexperienced direct laborers

c. The purchase of higher-quality direct materials

d. A machine being out of alignment

Which of the following situations would normally not indicate that a standard cost should be revised?

a. A change in labor-rates as a result of a new labor union contract.

b. A change in technology or basic production methods

c. A past history of unfavorable variances

d. An increase in the price of a raw material due to a world-wide shortage.