Huifen had 0.4 of his pens left after selling 816 of them at $0.40 each. He sold 0.75 of the remainder at $0.25 each. How much did he get from the sale his pens?

Answer 1

After selling 816 pens, Huifen had 100% - 40% = 60% of his pens left.
Since the remaining pens sold at $0.25 each, Huifen made $0.25 x 0.75 = ${{{highlight(0.1875)}}} from the sale of each pen.
Hence, Huifen earned a total of $816 x $0.40 = ${{{highlight(326.4)}}} from selling 816 pens.
He earned $0.1875 x 0.6 x 816 = ${{{highlight(90.72)}}} from selling the remaining pens.
Therefore, Huifen got a total of $326.4 + $90.72 = ${{{highlight(417.12)}}} from the sale of his pens. Answer: \boxed{417.12}.