Again, this is simple, just hard to explain how got answer.?

Question

Jess spent 1 1/2 hours on the internet. She spent 4/5 of this time researching for her history report and the rest of the time surfing the net. How many minutes did she surf the Net? Please explain in detail or whatever how you arrived at your answer. I REALLY need help.

Answer 1

The answer is 18 (the below is how I arrived at this answer)

1 1/2 hours = 90 minutes
(1 hour = 60 minutes, so add 1 hour plus half and hour (60 min. + 30 min.)

How long did she spend researching?
72 Minutes

90 * (4/5) = 72 Minutes
(She spent 4/5 of her time researching so multiply your available time by the time she spent researching)

90 - 72 = 18

(Now that you have have found out how many minutes she spent researching, take that value away from your available time to give you the time that she spent surfing the net.)

The answer is 18 (the above is how I arrived at this answer)

...or you can just multiply 90 * the fraction of the unknown

(90) * (1/5) = 18 Minutes

I like the uppermost solution better, because it is easier to explain than this answer. (You will soon understand it better; like you said, it IS NOT hard.)

Answer 2

First I assigned each variable a letter: For hours spent on history report, I used H. For hours spent on surfing I used S. Then I set up the first equation:
H hours on the internet+S hours on the internet=1 1/2 hours total spent on the internet, or 3/2 hours total spent(it's easier to do the equation if you convert to improper fraction).
Next, I set up the second equation:
H=3/2 *4/5 (* means multiply). One way to tell that you multiply in this situation is because the problem uses the word of.
The answer to that equation comes to 6/5, so H=6/5.
Finally, I plug in that answer to the first equation (H+S=3/2):

6/5+S=3/2
To get the answer, subtract 6/5 from each side, leaving you with
S=3/10

Therefore, the amount of time spent surfing the net was 3/10 of an hour. You can double check this answer by adding the S+H to make sure it equals 1 1/2:
6/5+3/10=1 1/2 :)

Hope this helps

Answer 3

It's been a while since I've done homework...let me see.

1 1/2 hours is 90 minutes. 4/5 of 90 minutes is 72 minutes (time she spent doing her history report). Therefore the time she spent surfing was 18. An easier way is to do it backwards. (1/5 of 90 is 18 minutes.)

What teenager only surfs for 18 minutes?

Answer 4

First, change the hours into minutes: 1 1/2 hours = 90 minutes, right? Now, you have to divide 90 into fifths. How many fifths are there in 90? 90 divided by 5 = 18. There are 18 fifths in 90. Therefore one fifth is 18. So if she spent four out of five fifths doing research, then she must have spent one fifth surfing the net. We already know that one fifth is 18. So the answer is 18 minutes.

Answer 5

1 1/2 hours =90 miutes
4/5 of 90minutes = 72 minutes
therefore the remaining 18 minutes was spent surfing the net

Answer 6

She spent 90 min. on the net. If she spent 4/5 of her time researching, you have 1/5 left for surfing. 90*1/5=18 min

Answer 7

1/5 of 90 minutes is 18. 5/5 is total amount of time spent. 4/5 was research so 5/5-4/5 = 1/5 is time surfing.

Answer 8

1 1/2 hours equals 90 minutes.

90 divided by 5 equals 18.

so she spent 18 minutes surfing the net.

Answer 9

gotta change everything into minutes, and it will make clearer sense to you:

1 1/2 hours = 3/2 hr * 60 min/hr = 90 minutes on the internet
4/5 * 90 = 72 minutes for history report
1/5 * 90 = 18 minutes on the net

(or you could do 90 - 72 = 18..)

hope this helps

Answer 10

90 minutes times 1/5 = 18 minutes