Equation - examples - page 49

1. Bricklayers
Seven bricklayers will build the house in 630 days. How many bricklayers do we need to take after 150 days to complete the building for (additional) 336 days?
2. Sales off
The price has decreased by 20%. How many percents do I have to raise the new price to be the same as before the cut?
3. Highway tunnel
The highway tunnel was built from two ends in the north-south direction. The average daily performance of the "northern party" rasters was higher than the average daily power of the "southern party" of the rasters. After 55 business days, both parties met.
4. Acid evaporation
How many kilograms of water do we have to evaporate from 100 kg of 32% acid to make it 80% concentration?
5. Water reservoir
One drain hole emptied the water from the tank for 20 hours, with the second drain for 30 hours. How long will the water drain from this tank if we open two drains simultaneously?
6. Clogging
How much distilled water must the pharmacist add to 30g of a 30% hydrogen peroxide solution to obtain a 3% solution to clogging?
7. The rod
The rod has a length of 90cm. Half is painted blue, the third is red and the rest is yellow. How long is the yellow part of the rod?
8. Merchant
The merchant lower cost by 10% in December when it was not sold. Again in January lower cost by 20% and now costs 576 €. A. How much the goods stood originally? B, how much cost the goods after the first lowering? C, How many percents totally merchant lo
9. Tank 11
When 150 litres has been drawn from a tank it is 3/8 full, how many litres will the tank hold?
10. Express train
International express train drove from Kosice to Teplice. In the first 279 km, the track was repaired, and therefore it was moving at a speed of 10km/h less than it was scheduled to drive. The rest of the 465 km trip has increased the speed by 8 km/h than.
11. Five pupils
Five pupils clean 30 chairs one hour before four pupils. How many chairs clean one pupil in 1 hour?
12. Four painters
The company sent four painters to paint the school. They should be done in 12 days. After three days, one painter got ill. How long will the remaining painters paint the school?
13. Find parameters
Find parameters of the circle in the plane - coordinates of center and radius: ?
14. Girls
The boys and girls in the class formed without the rest of the fives, 2 girls and 3 boys. There are 6 girls missing to create mixed pairs (1 boy and 1 girl). How many girls are in the classroom?
15. Flowers 2
Cha cruz has a garden. The ratio roses to tulips is 2 : 5, the ratio of roses to orchids is 7 : 6. Cha cruz wonders what the ratio of tulips to orchids is. If Cha cruz has 183 plants, how many of each kind are there?
16. Spherical tank
The tank of a water tower is a sphere of radius 35ft. If the tank is filled to one quarter of full, what is the height of the water?
17. Two bricks
One brick weighs 1kg and half a brick, how many weigh two bricks?
18. Boys to girls
The ratio of boys to girls in a party is 3:5 . If 6 more boys arrived and 4 girls left the party, the ratio of boys to girls would be 5:6 . How many are in the party originally?
19. Pupils
There are 350 girls in the school, and the other 30% of the total number of pupils are boys. How many pupils does the school have?
20. Calculate
Calculate the length of a side of the equilateral triangle with an area of 50cm2.

Do you have an interesting mathematical example that you can't solve it? Enter it, and we can try to solve it.

To this e-mail address, we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.

Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation?