Answer:
$5.76
Step-by-step explanation:
First, calculate the current (sale) price per pound. Noting that 10% off results in a multiplier of (1.00 - 0.10), or 0.90, and that the sale price is thus 0.90($1.60/lb), or $1.44/lb.
Four pounds of apples at this price would be (4 lb)($1.44/lb) = $5.76