The product of 3305 and the 1-digit integer x is a 5-digit integer. The units (ones) digit of the product is 5 and the hundreds digit is y. If A is the set of all possible values of x and B is the set all possible values of y, then which of the following gives the members of A and B?
A B
{1,3,5,7,9} {0,1,2,3,4,5,6,7,8,9}
{1,3,5,7,9} {1,3,5,7,9}
{3,5,7,9} {1,5,7,9}
{5,7,9} {1,5,9}
units代表各个位数,ones个位数,1 digit一位数
这种题目就慢慢试吧
3305乘上一个整数位5位数,n只能为5,7,9,相应地百位数是5,1,7
When you are translating english to math, "product" means multiplication, and "is" translates to equals sign
so 3,305 x X = a five digit integer