[計量] How many positive integers less ...

看板GRE (GRE入學考試)作者 (a Who)時間16年前 (2009/09/30 16:42), 編輯推噓1(104)
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How many positive integers less than 20 are equal to the sum of a pisitive multiple of 3 and a positive multiple of 4 ? A) Two B) Five C) Seven D) Ten E) Nineteen 答案 D。 我 ... 看不懂題目的意思 ... 囧" 請高手指點! -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 218.160.177.140

09/30 16:43, , 1F
有多少的數是3的倍數加4的倍數,小於20的
09/30 16:43, 1F

09/30 16:44, , 2F
7=3+4 10=6+4 11=3+8 13=4+9 15=12+3 16=12+4
09/30 16:44, 2F

09/30 16:46, , 3F
17= 9+8 18=6+12 19=16+3 20=8+12 共10個
09/30 16:46, 3F

09/30 16:46, , 4F
講錯,`沒20 14=6+8
09/30 16:46, 4F

09/30 16:50, , 5F
原來是這樣,大感謝~^^
09/30 16:50, 5F
文章代碼(AID): #1AmndUsV (GRE)
文章代碼(AID): #1AmndUsV (GRE)