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奇偶相加的规律 = corak tambah genap dan ganjil 奇数加偶数一定是奇数；偶数加偶数是偶数；奇数加奇数也是偶数。45 是奇数，正好可以由一个奇数加一个偶数得到，所以这道题有答案。 例子：11 + 20 = 31（奇 + 偶 = 奇）；13 + 15 = 28（奇 + 奇 = 偶）。 注意：如果总数是偶数，就不可能是一奇一偶。

odd and even sums = corak tambah genap dan ganjil Odd + even is always odd; even + even is even; odd + odd is also even. 45 is odd, so it can be made from one odd number and one even number, and the puzzle has answers. Example: 11 + 20 = 31 (odd + even = odd); 13 + 15 = 28 (odd + odd = even). Watch out: if the total were even, it could not be one odd and one even number.

有系统地列出 = senaraikan secara bersistem 先让 a 取最小的奇数 1，再依次取 3、5、7……，每次用 b = 45 − a 求出 b。这样一行一行列成表，就不会漏掉或重复。可以看到每个 b 都是偶数。 例子：a = 21 时，b = 45 − 21 = 24。 注意：如果两种水果都至少有一个，a 最大是 43；0 也是偶数，若允许没有番石榴（b = 0），a 也可以是 45。

list in an orderly way = senaraikan secara bersistem Start with the smallest odd number, a = 1, then take 3, 5, 7 and so on, each time working out b = 45 − a. A table keeps the pairs in order so none are missed or repeated. Every b turns out to be even. Example: when a = 21, b = 45 − 21 = 24. Watch out: if there is at least one of each fruit, a goes up to 43; since 0 is even, a could be 45 if b = 0 were allowed.

逐项检查 = semak setiap syarat 题目要找出同时符合全部条件的一组 a 和 b。每一组都要检查三件事：a 是不是奇数（看个位）；b 是不是偶数（看个位）；a + b 是不是刚好等于 45。三项都对才算符合，有一项不对就划掉。 例子：a = 9、b = 36：9 是奇数，36 是偶数，9 + 36 = 45，三项都符合。 注意：有的组奇偶对了但总数不对，有的组总数对了但奇偶放反了，三个条件缺一不可。

check each condition = semak setiap syarat Find the pair that meets every condition. For each pair check three things: is a odd (look at its ones digit), is b even, and do they add up to exactly 45? Cross out any pair that fails one check. Example: a = 9 and b = 36: 9 is odd, 36 is even and 9 + 36 = 45, so all three checks pass. Watch out: some pairs have the right odd and even numbers but the wrong total, and some have the right total with odd and even swapped.