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1. The Heron Sea has a volume of 1.4x10^14 litres, of which 12% is salt.
The Cobalt Sea has a volume of 8.5x 10^12 litres, of which 8% is salt.
What is the percentage decrease in the volume of salt from the Heron Sea to the Cobalt Sea?
2. (Original post by neharajput)
The Heron Sea has a volume of 1.4x10^14 litres, of which 12% is salt.
The Cobalt Sea has a volume of 8.5x 10^12 litres, of which 8% is salt.
What is the percentage decrease in the volume of salt from the Heron Sea to the Cobalt Sea?
Not allowed to give full answers/solutions here so I'll try to guide you.

How far have you got with this? Tell me which stage you're on and I'll nudge you in the right direction.
3. (Original post by Hydeman)
Not allowed to give full answers/solutions here so I'll try to guide you.

How far have you got with this? Tell me which stage you're on and I'll nudge you in the right direction.
I literally have no idea where to start and I've been stuck on it with my friend for hours
4. (Original post by neharajput)
I literally have no idea where to start and I've been stuck on it with my friend for hours
Alright, so start with finding out how much salt there is in each sea. How do you think this can be done?
5. Find 12% of 1.4x10^14 and 8% of 8.5x10^12
12% would be 1.68x10^13
8% would be 6.8x10^11
6. (Original post by neharajput)
Find 12% of 1.4x10^14 and 8% of 8.5x10^12
12% would be 1.68x10^13
8% would be 6.8x10^11
Great. Now: do you know how to work out percentage decreases?
7. Work out the difference (decrease) between the two numbers you are comparing. Then you would divide the decrease by the original number and multiply the answer by 100. But I'm unsure of how to do this part.
8. (Original post by neharajput)
Work out the difference (decrease) between the two numbers you are comparing. Then you would divide the decrease by the original number and multiply the answer by 100. But I'm unsure of how to do this part.
Hi. Sorry for the late reply; you didn't quote me so I didn't get a notification that you'd replied.

You're spot on about how to work out the percentage decrease. So here's the question and your working so far:

(Original post by neharajput)
The Heron Sea has a volume of 1.4x10^14 litres, of which 12% is salt.
The Cobalt Sea has a volume of 8.5x 10^12 litres, of which 8% is salt.
What is the percentage decrease in the volume of salt from the Heron Sea to the Cobalt Sea?
(Original post by neharajput)
Find 12% of 1.4x10^14 and 8% of 8.5x10^12
12% would be 1.68x10^13 -- A
8% would be 6.8x10^11 -- B
So you'd do A - B = ?. This would give you the difference between them. You then divide the answer to that by 1.68 x 1013.

Have a go at doing it first and then check your answer with the one in the spoiler.

Spoiler:
Show
(from above) A - B = 1.612 x 1013 litres

(1.612 x 1013)/1.68 x 1013 x 100 = 95.95 percent

Have a feeling this might be wrong but it's all I can think of for the time being. xD
9. Thank you so much for your help, I'll let you know if my answer is the same as the spoiler after I work it out. but thankyou
(Original post by Hydeman)
Hi. Sorry for the late reply; you didn't quote me so I didn't get a notification that you'd replied.

You're spot on about how to work out the percentage decrease. So here's the question and your working so far:

So you'd do A - B = ?. This would give you the difference between them. You then divide the answer to that by 1.68 x 1013.

Have a go at doing it first and then check your answer with the one in the spoiler.
Spoiler:
Show
(from above) A - B = 1.612 x 1013 litres

(1.612 x 1013)/1.68 x 1013 x 100 = 95.95 percent

Have a feeling this might be wrong but it's all I can think of for the time being. xD

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Updated: October 30, 2015
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