April 27, 2009 Math Homework

Tuesday, April 28, 2009
Nicko's Stuff:
Questions 9 to 12

#9
The distance to Grandma's house is 4/5 of the distance to Uncle Glen's. If Uncle Glen's house is
3 1/2 hours away, how long will it take to get to Grandma's house if you travel at the same speed?

To multiply fractions, it would be way easier if there was no whole number. Let's turn 3 1/2 in to an improper fraction. To do this, you multiply the denominator by the whole number and add the numerator.
3 x 2 + 1 = 7

Now we have 4/5 x 7/2. Now we multiply the numerator then the denominator.
4 x 7 = 28
5 x 2 = 10
Now we have 28/10 as an answer. We then simplify the answer. 28/10 = 2 and 8/10. We can even simplify this more to 2 and 1/4.

Now we know that it will take 2 and 1/4 hours to reach Grandma's house.

#10

It takes 3/5 of a tank of gas to get to work and back each day. How much gas is used over 5 work days?

In each 5 days, 3/5 is used. So all you have to do is multiply the numerator by 5.
5 x 3 = 15.
15/5 or 3 tanks
In five days it takes 3 tanks of gas to get to work.

#11

Owen is 2 1/4 times as old as Robin. When Robin celebrates his 8th b-day, how will old Owen be?

8 x 2 1/4 is the basic question. Again we should not multiply mixed fractions, so we convert.
2 x 4 + 1 = 9
The question becomes: 8 x 9/4

*When we have a whole number being multiplied to a fraction, all you have to do is multiply the whole by the numerator and use the same denominator.*

72/4 is what it will become but now we have to simplify. Both numerator are even so the can be divided by two.
36/2 again they are both even.
18/1 is the most simple form possible. It's basically just 18.
Owen will then be 18 when Robin becomes 8.

#12

The Karate club is arranging a grading for its members. It takes 3 1/4 hours to test a group of 4 candidates. How long will the club need the gym in order to process 3 groups of 4 candidates each?

The question is basically asking: 3 x 3 1/4.
3 x 13/4
39/4
9 and 3/4

I got lazy and didn't show my work so I hope you figured out what I did. If not, check out the other question i did.

It will take 9 and 45 minutes to test 3 groups of 4 candidates each.

_Nicko---- ~_~" ----Lissa_

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