The correct answers are: More efficient procedures have been put in place causing a fall in direct labour costs and administrative overheads have risen; The cost of raw materials has fallen and non-manufacturing wages and salaries have increased.

If more efficient procedures have been put into place causing a fall in direct labour costs, or the cost of raw materials has fallen, the gross profit percentage will rise.

If administrative overheads or non-manufacturing wages and salaries have risen, the net profit percentage will fall.

If the cost of energy for manufacturing, the cost of raw materials or the depreciation on assets used in manufacturing have risen, the gross profit percentage will fall.

If administrative overheads have fallen, the net profit percentage will rise.

An increase in sales volume does not have any effect on the gross or net profit percentages unless discounts have been given.