Question

Which number has only two factors
299
989
749
Or
1009

Answer 1

749, when you do the stem leaf plot, you get that

Answer 2

749 is divisible by 7 and 107, so that's out. 299 is a product of 13 and 23, so that ones also out. And 989 is divisible by 23 and 43. Which leaves 1009, divisible only by 1 and 1009 :)