Watermelon in the sun math riddle
There is a 100 pound watermelon laying out in the sun. 89 percent of the watermelon’s weight is water. After laying out for a few hours 88 percent of the watermelon’s weight is water.
How much water evaporated?
8.33 lbs of water evaporated
(89-x) = (100-x)*.88
89-x = 88-.88x
1-x = -.88x
1=.12x
x=8.33
Where:
89-x = water loss
100-x = watermelon loss
.88 = new ratio
100-8.33=91.67 lbs (new watermelon weight)
89-8.33= 80.67 lbs (new water weight)
80.67/91.67 = 88%
1 pound of water evaporated. If the watermelon ways 100 pounds 89% would be 89 pounds.
But that would leave the watermelon at 99lbs and 88/99 isn’t 88%
11*(100/12)=91.6 gm
Almost there, but you answered the wrong question. It didn’t ask how much the watermelon weighs now, but how much water evaporated, which, by assumption, it wants that in pounds as that is the only unit of measurement given in the question.
Perhaps none of the water evaporated but instead 1% of the water was converted into the mass of the watermelon by the sun’s energy
After thinking about this a little more… The watermelon grew in size/weight potentially altering the weight in water ratio
Initial weight of non water content is 11 lbs.
Let X be the water wt. after losing water then
X/(11+X)=0.88
Solving this gives X=80.66
So lost water is 89-80.66
i.e. 8.33lbs
Simplified answer because of the way the question was worded would be 1 % of the water evaporated. This answer would suffice as it did not ask for how much the water weighed, it simply asked, ” How much water evaporated ?”.
Even in percentage terms, 1% would not be correct. Remember, percentages are relative so if dividend is not kept constant, then percentage will change. The first answer 8.33 is correct. That is equal to 9.3% of 89 lbs of water lost.
Your Answer
More puzzles to try-
What is the logic behind these ?
3 + 3 = 3 5 + 4 = 4 1 + 0 = 3 2 + 3 = 4 ...Read More »Defective stack of coins puzzle
There are 10 stacks of 10 coins each. Each coin weights 10 gms. However, one stack of coins is defective ...Read More »Which clock works best?
Which clock works best? The one that loses a minute a day or the one that doesn’t work at all?Read More »(Advanced) Cheryl’s Birthday Puzzle
Paul, Sam and Dean are assigned the task of figuring out two numbers. They get the following information: Both numbers ...Read More »Five greedy pirates and gold coin distribution Puzzle
Five puzzleFry ship’s pirates have obtained 100 gold coins and have to divide up the loot. The pirates are all ...Read More »Magical flowers!!
A devotee goes to three temples, temple1, temple2 and temple3 one after the other. In front of each temple, there ...Read More »Tuesday, Thursday what are other two days staring with T?
Four days are there which start with the letter ‘T‘. I can remember only two of them as “Tuesday , Thursday”. ...Read More »How could only 3 apples left
Two fathers took their sons to a fruit stall. Each man and son bought an apple, But when they returned ...Read More »How Many Eggs ?
A farmer is taking her eggs to the market in a cart, but she hits a pothole, which knocks over ...Read More »HARD MATHS – How much faster is one train from other Puzzle
Two trains starting at same time, one from Bangalore to Mysore and other in opposite direction arrive at their destination ...Read More »Most Analytical GOOGLE INTERVIEW Question Revealed
Let it be simple and as direct as possible. Interviewer : Tell me how much time (in days) and money would ...Read More »Lateral thinking sequence Puzzle
Solve this logic sequence puzzle by the correct digit- 8080 = 6 1357 = 0 2022 = 1 1999 = ...Read More »How did he know?
A man leaves his house in the morning to go to office and kisses his wife. In the evening on ...Read More »Pizza Cost Math Brain Teaser
Jasmine, Thibault, and Noah were having a night out and decided to order a pizza for $10. It turned out ...Read More »Which letter replaces the question mark
Which letter replaces the question markRead More »Which room is safest puzzle
A murderer is condemned to death. He has to choose between three rooms. The first is full of raging fires, ...Read More »Richie’s Number System
Richie established a very strange number system. According to her claim for different combination of 0 and 2 you will ...Read More »Srabon wanted to pass
The result of math class test came out. Fariha’s mark was an even number. Srabon got a prime!! Nabila got ...Read More »Become Normal!!
Robi is a very serious student. On the first day of this year his seriousness for study was 1 hour. ...Read More »Sakib Knows The Number!
Ragib: I got digits of a 2 digit number Sakib: Is it an odd? Ragib: Yes. Moreover, the sum of ...Read More »
