Main content

## Arithmetic

### Course: Arithmetic > Unit 10

Lesson 4: Multiplying fractions and whole numbers word problems# Multiplying fractions by whole numbers word problem

Lindsay solves a word problem that involves multiplying a fraction by a whole number.

## Want to join the conversation?

- Where is sal I like when he does it(21 votes)
- HE is in your mind.(0 votes)

- where is sal khan(8 votes)
- this is a little bit hard ngl(5 votes)
- but where is SALL(4 votes)
- im used to sal. where is he(4 votes)
- yay where is saL?(1 vote)
- yay where is sal he's the best!(1 vote)
- i've watched the video 5 times already and it's not registering. does anyone know why that is happening and how i can fix it?(1 vote)

## Video transcript

- [Voiceover] Rishi spend
3/4 of an hour for two days working on his science project. Kyle spent 1/4 of an hour for six days working on his science project. Who spent more time on
his science project? So we wanna know who spent more time, and to do that we need to first know the amount of time Rishi and Kyle each spent on their science projects. So let's start with Rishi, and
see what we know about Rishi. Rishi spent 3/4 of an hour for two days, so two times, he spent 3/4 of an hour. Or another way we could say this, is he spent 3/4 of an hour once, plus on a second day he
spent another 3/4 of an hour. So 3/4 plus another 3/4 will give us a total of
6/4, or six quarter hours, that Rishi spent on his science project. Now let's look at Kyle. Kyle spent a 1/4 of an
hour, so here's Kyle. Kyle spent 1/4 of an hour, but he did this for six days, so six times, he spent 1/4 of an hour. Or we could say that Kyle
spent 1/4 of an hour one day, plus 1/4 of an hour a second day, 1/4 of an hour a third day, a fourth day, a fifth day, and then a sixth
day he spent 1/4 of an hour. So six times, one, two, three, four, five, six, he spent a quarter, or 1/4 of an hour working on his project. So if we have six 1/4s, then we have a total of 6/4. So Kyle spent 6/4, or six quarter hours. And now back to our question, now that we know how
much each of them spent, who spent more time working
on his science project? Rishi with 6/4 hours,
or Kyle with 6/4 hours? And the answer here, of course, is that these are equal,
these are the same. Rishi and Kyle spent
the same amount of time, so we could say the same amount of time working on each
other their science projects.