Grades 3-4 Video Solutions 2022-2022_3-4

Video Transcription

Problem number 9. 5 cars numbered 1, 2, 3, 4 and 5 are moving in the same direction. The last car, 5, passes the 2 cars ahead of it.  Next, the second to last car passes the 2 cars ahead of it. Next, the second to last car passes the 2 cars ahead of it. Finally, the middle car passes the 2 cars ahead of it.  In what order are the cars now?  Here are the 5 cars in order 1, 2, 3, 4 and 5. And they are all moving to the left. To solve this problem, we will need to take it step by step.  We know that the last car passes the 2 cars ahead of it. But then, the next to last car is probably not going to be car number 4 again. It will be a different car.  So we need to go through all the steps one at a time to figure out what the order is.  We can just write out the numbers and go from there. In the beginning you have 1, 2, 3, 4, and 5. But what happens in the first step is the last car passes the two cars ahead of it.  So now car number 5 gets in front of car number 4 and car number 3. So it's here. So the order is 1, 2, 5, 3, 4. After this, the second to last car passes the two cars ahead of it.  At this point the next to last car is car 3 and it gets ahead of car 5 and car 2. So the order becomes 1, 3, 2, 5, 4. Then finally the middle car passes the two cars ahead of it.  The middle car is 2, so it gets into first place here. The order becomes 2, 1, 3, 5, 4. This answer choice is B. Here's an animation to help us see this.

Video Summary

Summary Not Available