Energy saving

They were released three different, independent inventions saving 12%, 15% and 25% energy. Some considered that while the use of these inventions, the total savings will be 12% + 15% + 25% = 52%. Is this true? How much percent of energy will save all three inventions together?

Correct result:

p =  43.9 %

Solution:

$p=100\cdot (1-(1-0.12)\cdot (1-0.15)\cdot (1-0.25))=43.9\mathrm{\%}$

Try another example

Showing 0 comments:

Next similar math problems:

• New refrigerator
  New refrigerator sells for 1024 USD, Monday will be 25% discount. How much USD will save, and what will be the price?
• Saving
  Allen save € 2860 to buy a car. Yet it lacks save 55% of the car price. How much is the car?
• Adding percentages
  55%+36%+88%+71%+100=63% what is whole (X)? Percents can be added directly together if they are taken from the same whole, which means they have the same base amount. .. . You would add the two percentages to find the total amount.
• Cinema tickets
  Cinema sold 180 tickets this Thursday, which is 20%. Monday 14%, Tuesday 6%, Wednesday 9%, Friday 24%, Saturday 12%, and Sunday 15%. How many tickets were sold per week?
• Farmland
  Farmers seeded maize to 45 ha, which is 15% of their total farmland. How many hectares of fields they have?
• Two shops
  In two different shops, the same skis had the same price. In the first, however, they first became more expensive by 20% and then cheaper by 5%. In the second, they were first cheaper by 5% and then more expensive by 30%, so after these adjustments in the
• Painting
  The room is long 50 meters and wide 60dm and 300 cm high. Calculate how much it will cost painting if area of windows and doors is 15% of the total area. One square meter cost 50cents.
• Statistical XY file
  Year; money spent on advertising; profit (three values each row) 2008 2 12 2009 5 20 2010 7 25 2011 11 26 2012 15 40 1. draw a scatter diagram depicting the data. 2. calculate the Pearson's correlation coefficient. 3. determine the linear regression equat
• Ski class
  Class attend 30 boys and some number of girls. Ski training was attended by 28 boys and all the girls, which was 95% of all students. How many girls attend this class? How many percent is that?
• Company
  After increasing the number of employees by 15% company has 253 employees. How many employees take?
• Speed of Slovakian trains
  Rudolf decided to take the train from the station 'Ostratice' to 'Horné Ozorovce'. In the train timetables found train Os 5409 : km 0 Chynorany 15:17 5 Ostratice 15:23 15:23 8 Rybany 15:27 15:27 10 Dolné Naštice 15:31 15:31 14 Bánovce nad Bebravou 15:35 1
• Training
  The table contains tennis training schedule for Saturday's younger students during the winter indoor season. Before the start of the summer season is preparing a new training schedule. Tomas Kucera will be able to practice only in the morning, sisters Kov
• The room
  The room has a cuboid shape with dimensions: length 50m and width 60dm and height 300cm. Calculate how much this room will cost paint (floor is not painted) if the window and door area is 15% of the total area and 1m2 cost 15 euro.
• Alcohol
  6l 48% alcohol, how much 52% alcohol must be added to give 50% alcohol?
• Profits
  Two members will make profit 52 000, - EUR. The forst earned 8% more and the second 10% more and thus earned together 56 700, - EUR. How many will initially each earn?
• Siblings
  Three siblings had saved up a total of 1,274 CZK. Peter had saved up to 15% more than Jirka and Hanka 10% less than Peter. How much money they saved each one of them?
• Iron
  Iron ore contains 54% iron. How much ore is needed to produce 23 tons of iron?