Glina - here's those problems that you posted:
The ratio of 2 to 5=(?)%
1. Set up an equation that you can work with. Put the 2 over the 5 and set it equal to x over 100 (since percentage is always out of 100%), x = percentage.
2/5 = x/100
2. Solve the equation by cross multiplying (multiply diagonally each way)
5x = 100*2
5x = 200
3. Finally, divide by 5 so that it leaves x by itself (this is the percentage you want to figure out)
5x/5 = 200/5
This leaves: x = 40
The answer is 40/100 or 40%
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3/16=(/)%x3/4
1. To start this problem, write everything out. Remember that the fraction (/)% is going to be an unknown number (x) over 100 (100%).
3/16 = x/100 * 3/4
2. On the right side of the equals sign, multiply across the top and bottom (x times 3 on top, 100 times 4 on bottom) and you should get:
3/16 = 3x/400
3. Cross multiply to get (3x times 16, 400 times 3)
48x = 1200
48x/48 = 1200/48
x = 25
The answer is 25/100 or 25%
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0.6% of 18 equals:
1. Try to imagine that this is just a common whole number like 10%. The first thing you would do in that case is put a decimal all the way to to right of the 10 and move it to the left 2 spaces to get .10
So with this one you do the same
0.6% = .006
.006 * 18 = ___
When you multiply you should get .108
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8% of x is equal to 48. Solve for x
1. Start by converting the percentage into a decimal like in the last problem
8% = .08
2. Set an equation
.08x = 48
3. Solve for x
.08x/.08 = 48/.08
x = 600
4. You can double check your answer by plugging it back in as x
.08(600) = 48
48 = 48, so it is correct
Hope that helps and isn't more confusing - be sure to really study and know the percentages/fractions (my exam had a lot) - maybe someone can chime in with some other tips. Good luck!
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