Riaz wants to use the number sentence shown to solve a problem. 12 ÷ 3 = ? which problem could be solved using this number sentence? a) a pet store has 12 cats. if 3 of them are sold, how many cats have not been sold? b) a key chain can hold 3 keys. if there are a total of 12 keys, how many key chains are there? c) a necklace has 3 blue beads and 12 green beads. how many beads does the necklace have in all? d) a sewing machine can sew 1 button in 3 seconds. how many seconds will it take to sew 12 buttons?

B)A key chain can hold 3 keys. If there are a total of 12 keys, how many key chains are there?

The answer is B. There are certain keywords that can show you what the sign will be. 

"A pet store has 12 cats. If 3 of them are sold, how many cats have not been sold?" That is basically asking you to subtracted. Can you see how? "How many cats have NOT been sold." That's the key right there. so it's obviously not that one. 

"A key chain can hold 3 keys. If there are a total of 12 keys, how many key chains are there?" That is asking you to divide 12 keys into key chains that can hold 3 keys. Did you take the hint? 

Answer C is obvious because the phrase "In all" is addition. 

And the answer isn't D either. Does this make sense?