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# Multiplying fractions word problem: bike

This video is all about understanding how to multiply fractions and mixed numbers. Watch as the steps are explained in a simple and fun way. Created by Sal Khan.

## Want to join the conversation?

• isn't 3 1/3's improper fraction supposed to be 10/3
• Hey, the answer is 10/3 but he just did 9/3 + 1/3 to simplify how to find ten thirds here
• I didn't get really why we should multiply! I do on paper though. But Sal understand that right way! Can someone explain that why should we multiply?
• As you learn word problems, you will find that there are a variety of formulas that occur and that you need to learn. This problem uses one of those formulas. Specifically, it used the formula: Distance = Rate (Time).

Sal knows this formula, so he knows he needs to multiply the speed/ rate (the 1/5 miles per minutes) times the time (the 3 1/3 minutes).

Hope this helps.
• umm, why did he not simplify the 10 and the 5 before multiplying them? that would have make things much easier
• He could but maybe it would be easier for some people if he does the other way.
• Isn't 3 times 3 plus 1 10/3? Why'd he right 9/3 + 1/3?
• what if we divide what will we get ?
• at to about he multiplies 1/5X 3 + 3X like 1/3. How is this possible?
• Wait so I don't get it is this how u do it? for example 1/5 x 3/4 so first you multiply the numerator with the numerator which is 4 x 5= 20 and then you multiply the dinomerator's which is 1 x 3= 3 so then the answer would be 3/20? Is that right?
• Is it 9/3 or 10/3? I know the answer is 10/3, but did Sal mean to write 9/3? I mean, was 9/3 his answer, or was 10/3 his answer?
(1 vote)
• I assume you are referring to the section at about in the video. Sal is converting 3 1/3 into 10/3. He wrote it out in steps. 3 1/3 = (3*3)/3 + 1/3 = 9/3+1/3 = 10/3. He writes the result of 10/3 at about in the video. The 9/3 is just an intermediate work result.
Hope this helps.
• Is there a faster way?
anybody