Find the Original Price & a word problem ~ PLEASE SHOW HOW YOU DID IT

1) Retail price: $40 Markup Percent: 85% 2) Sale Price: $199 Discount Percent: 20%

Word problem
You bought a pair of jeans at an outlet store. You see the same jeans at ANOTHER store for $51, which is 36% more than you paid for them at the outlet store. How much did you pay for the jeans at the outlet store?

I tried all of these problems three times EACH and I keep on getting the same answer, which is wrong; so can you please help me & show your work so I can understand what I am doing wrong?? Thank you SO MUCH!!

1) Retail price: $40 Markup Percent: 85%

MP = OP + 85% of OP
40 = x + 85/100 *x
40 = (100x +85x)100
40*100 = 185x
x = 4000/185

x = 21.62
OP = $ 21.62


2) Sale Price: $199 Discount Percent: 20%

SP = OP -20% of OP
199 = x - 20/100 *x
199 = (100x -20x )/ 100
19900 = 80x
x = 248.75

OP = $248.75

3)
51 = x +36/100 *x
51 = 136x/100
x = 37.5
U paid = $ 37.5 at another store

36 51 this is your proportion, then you cross multiply so 36n=5100
100 n divide each side by 36 and you get about 141.67 that's how much the jeans cost

40 x .85 = 34
40 + 34 = 74

199 x .20 = 39.80
199 - 39.80 = 159.20 whenever you have a percent, it's best to put it in proportions, but during markup and discount you can change the percent to a decimal and subtract or add