Grades 3-4 Video Solutions 2012-2012_3-4

Video Transcription

Problem number 3. Father hangs the laundry outside on a clothesline. He wants to use as few pins as possible. For 3 towels, he needs 4 pins, as shown.  How many pins does he need for 9 towels? 8, 10, 12, 14, or 16? To solve this problem, we are going to make a chart. So, one side will be towels, and one side will be pins.  So, for one towel, we need 2 pins. It will look something like this. And these are the pins. And then, if we add another towel, here's the third pin. For 2 towels, we need 3 pins.  And for 3 towels, which is what we see in the picture, we need 4 pins. Now, if we look at this pattern, we see that there will be always one more pin than towels.  Which means, if there are 9 towels, that means we would need 10 pins. Which means, our answer is B, 10.

Video Summary

Problem number 3. Father hangs the laundry outside on a clothesline. He wants to use as few pins as possible. For 3 towels, he needs 4 pins, as shown. How many pins does he need for 9 towels? 8, 10, 12, 14, or 16? To solve this problem, we are going to make a chart. So, one side will be towels, and one side will be pins. So, for one towel, we need 2 pins. It will look something like this. And these are the pins. And then, if we add another towel, here's the third pin. For 2 towels, we need 3 pins. And for 3 towels, which is what we see in the picture, we need 4 pins. Now, if we look at this pattern, we see that there will be always one more pin than towels. Which means, if there are 9 towels, that means we would need 10 pins. Which means, our answer is B, 10.

Keywords

laundry

clothesline

towels

pins

pattern