176有一个图形题,4-inch by 4-inch的正方形,分成1-inch的个子对角线都画起来,这样一共有41个交点,如果是8-inch by 4-inch的长方形分成1-inch的格子,对角线依旧,那么交点有多少?可以理解为两个4inch的正方形拼起来,拼接处重叠的5个点减掉,应该是41*2-5=77个吧。
253 P(almond or something) 24 pounds, Q (walnut or something) 25 pounds. Use them to make 2 mixtures, X and Y. In X, P=4:1, in Y, P=1:5 (maybe the number is not exact), ask how many pounds is the X.我算了一个接近24 pounds的结果,没时间了不知对错。