Reverse percentage help?

if the number subtracted 30%, and you have 150 left over, that means 150 is 70%

(30+70) = 100% of the number you dont know

so .7 = 70%

.7 of the number you dont know is 150

.7(n)=150 ----divide each side by .7

which would be hard to do w/o calculator

but its 214.285...

sorry. but i dont know how you'd do it without a calculator. so i'm no help. good luck!

Q1. Let the required number be ' x '

30% of x = 30/100 of x = 3/10 of x = 3x/10 ........... (1)

Now " What number ( in our case we have assumed it to be x ) decreased by 30% gives 150 ". So we can change our language to " x decreased by 30% gives 150.

ie x - ( 3 x / 10 ) = 150

=> 7x /10 = 150

=> x = 150 * 10 / 7 = 1500 / 7 = 214.285.....

Hence the number = 214.285 .................. Answer Answer

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Q2. What number increased by 15% gives 25?

Proceeding in the same way we have --

Let the unknown number be ' x '.

So that 15% of x = 0.15 x

=> x + 0.15 x = 25

=> 1.15 x = 25

=> x = 25 / 1.15 = 21.73913...

Hence the required number = 21.74 ..... Answer Answer

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I'm not positive if this is right, but I think it is.

1. What number decreased by 30% gives 150.

Since off the top of our head we do not know what the original number is we will assign X to it.

Of the original number(X) we subtract 30%, so 30 percent of X would be .3X.

The equation would be X-(.3)X=150

.7X=150

X=150(10/7)

X=214.29, 214.29 - .3(214.29) = 150.

2. What number increased by 15% gives 25

So assign X to the original number. And X plus 15 percent of X = 25.

X+.15(X) = 25

1.15X=25

X= 25/1.15

X=21.73, 21.73 + .15(21.73) = 25

I hope this helps and is not too confusing.

does not appear as if a "opposite proportion" situation to me. His merchandising fee became 15% greater beneficial than he paid on the abode and 12% below he paid on the automobile. in case you had all started with the quantity he gained from the sales and had to discover the unique volume, that should have made it a "opposite proportion" situation.