CPhill

1200 (3/4)  =  900 are X

so....300 are Y

The difference cannot be 240 !!!

Let angle C =  x

Then angle B = 2x + 22

The angles sum  to 180....so....

A +  B + C  =180

86   + 2x + 22  + x = 180

3x + 108 = 180

3x = 180 - 108

3x =72

x = 72 / 3

x = 24 = angle C

Yep !!!!

Let the amount of money that you have at first =  X

Let the amount of money that your brother has = Y

So.....you give him 5......you have 5 less ad he has  5 more....so

X - 5  = Y + 5    →    X  = Y + 10      (1)

And after he gives you $25 you have 2  times as much as he does.... so.we have

X + 25  = 2 ( Y - 25)          (2)

Sub (1) into (2)

Y + 10 +25  = 2 (Y - 25)

Y+35  = 2Y - 50       rearrange as

50 + 35  =  2Y - Y

85  = Y        (he started with $85)

And you stared with Y + 10 = $95

Proof

You started with  95  he starts with 85

When you give him 5 you both have the same

If he gives you 25 you have 95 + 25 =   120   and he has   85 - 25 =  60   (you have twice as much !!! )

Assumig that the berries themselves lost no weight.....and I'm assuming that the "90%"  is 90% of the original water weight 

If the box of berries was 99%  water.....the weight of the water was  .99 * 200  =  198 kg

And the berries must weigh 200 - 198 = 2kg

If after two days, the water content was 90%, then the weight of the water = .90 * 200 = 180 kg

So.....the weight of the berries after two days =  180 + 2 =  182 kg

Using some trig

Note that cos (angle BDA)  =  -cos ( angle BDA)  = cos (angle CDA) 

 also  let  BD = CD  = x

and  5sqrt (2)  = sqrt (50)

Using the Law of Cosines (twice)

AB^2  =  x^2 + AD^2  - 2 (AD)(x) cos (BDA)

AC^2 = x^2 + AD^2 - 2(AD)(cos CDA)                simplify these

50 = x^2 + 53  - 2(AD)(X) cos (BDA)

70 = x^2 + 53 - 2(AD)(x) (-cos (BDA) 

50 = x^2 + 53 - 2(AD)(cos BDA)

70 = x^2 + 53 + 2(AD)( cos BDA)     add these equations

120 =  2x^2 + 106

120 - 106 = 2x^2

14 = 2x^2

7 = x^2

sqrt (7)  = x

So  BC  = 2x  =  2sqrt (7) = sqrt (  28)

Using Heron's formula to find the area

s = [ AB + BC + CD ] /  2  =  [ sqrt (50) + sqrt (28) + sqrt ( 70)  ] / 2

Area of ABC  =  sqrt [ s ( s - sqrt (50)) ( s - sqrt (28)) ( s -sqrt (70) ) ]

Using WolframAlpha to evaluate :

Area of ABC ≈   sqrt (346) ≈  18.6 units^2

Call the total amount of money that he has at first =  M

The backpack costs (3/7)M

The amount that remains = (4/7)M

(2/3)  of this =  (2/3)(4/7)M  = (8/21)M = money spent on purification bottles

Money spent of first aid kits = (M - 3/7 M - 8/21 M ) =   (4/21)M

Note that  the total difference between the cost of the purification bottles and the first aid  kits = 3 (14.80)

So

(8/21)M - (4/21) M = 3 (14.80)

(4/21)M = 44.40

M = 44.4 *(21/4)  ≈ $233.10

Amt spent on backpack ≈  (3/7)(233.10) ≈ $99.90

Amt spent on purification bottles = (8/21)(233.10) ≈ $88.80

I've had some  health problems.....thanks  for  thinking about me.....GOOD TO BE BACK!!!

Heck, Bosco.....you beat me to it  !!!

Here's an approach that only uses a little trial and error

Note that  999/9 = 111

So....let's assume that our number must have the form   1 0  __  ___  where the last two digits are unique

Note that successive multiples of 9 (after 999) are

1008

1017

1026 =  our number