请教一下112数学难题的第70题,how many positive integers can be expressed as a product of two or more of the prime numbers 5,7,11 and 13 if no one product is to include the same prime factor more than once?eightnineteneleventwelve答案选的是D,
2019-05-23
请教一下112数学难题的第70题,how many positive integers can be expressed as a product of two or more of the prime numbers 5,7,11 and 13 if no one product is to include the same prime factor more than once?eightnineteneleventwelve答案选的是D,
优质解答
product是乘积的意思.问题译文：如果没有一个乘积包括多于一次的同样素数/质数,那么由素数5,7,11,13表达的正整数有多少个?选项是8,9,10,11,12（个） 共11个,如下：5x7,5x11,5x13,7x11,7x13,11x13 5x7x11,5x7x13,5x11x13,7x11x13 5x7x11x13
product是乘积的意思.问题译文：如果没有一个乘积包括多于一次的同样素数/质数,那么由素数5,7,11,13表达的正整数有多少个?选项是8,9,10,11,12（个） 共11个,如下：5x7,5x11,5x13,7x11,7x13,11x13 5x7x11,5x7x13,5x11x13,7x11x13 5x7x11x13