A store sell mints for 50美分each or 4.8美元for a case of 12 mints.The cost per mint is what percent greater when the mints are purchased separately than when purchased in a case?第二道:if m is a positive integer,and if 3+16/m is an interger
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A store sell mints for 50美分each or 4.8美元for a case of 12 mints.The cost per mint is what percent greater when the mints are purchased separately than when purchased in a case?第二道:if m is a positive integer,and if 3+16/m is an interger
A store sell mints for 50美分each or 4.8美元for a case of 12 mints.The cost per mint is what percent greater when the mints are purchased separately than when purchased in a case?
第二道:if m is a positive integer,and if 3+16/m is an interger less than 19,which of the following must be true of A:m=19,B:m is even,C:m=16,D:m is a prime number E:m is a multiple of four 感激不尽!
A store sell mints for 50美分each or 4.8美元for a case of 12 mints.The cost per mint is what percent greater when the mints are purchased separately than when purchased in a case?第二道:if m is a positive integer,and if 3+16/m is an interger
翻译+
1.一家商店出售薄荷糖,50美分一块或者4.8美元一包(12个).问单独购买一块与购买一包相比较,一块薄荷糖的单价要高出百分之多少?
[50-(480/12)]/(480/12)=25%
2.已知m是一个正整数,3+16/m是一个小于19的整数,下列哪种说法一定正确?( )
A:m=19 B:m是偶数 C:m=16 D:m是质数 E:m是4的倍数
选B
A:3+16/19不是整数,A错误
B:∵3+16/m是一个小于19的整数
∴16/m是一个小于16的整数
∴m是16的因数
∵16的质因数是2
∴m是2的倍数,即m是偶数
C:3+16/2=11也是小于19的整数,m可以不是16,C不一定正确
D:3+16/4=7也是小于19的整数,m=4是合数,D错误
E:3+16/2=11也是小于19的整数,m=2不是4的倍数,E错误
最后:楼主加油!