# Grade - examples - page 212

1. The tub
If we drop the 5 l from the first tap and the from second 2 liters of water, the water in the tub will have a temperature of 25°C. If we drop 3 l from the first tap and from second 4 l of water, the water in the tub will have a temperature of 21°C. Determi
2. Mysterious number
The magician thinks the number: "The mysterious number is first divided by minus five, dividing the result by three, multiplying the number by ten, and dividing the resulting number by minus four. This gives result 5. Can you reveal the mysterious number?
3. Wave parameters
Calculate the speed of a wave if the frequency is 336 Hz and the wavelength is 10 m.
4. Pencil cut
Veronika cut 10cm pencil. Each turn, the pencil was reduced by 0.2mm. She turned the pencil 100 times. How many centimeters has a pencil now?
5. The lowest
The lowest temperature on Thursday was 20°C. The lowest temperature on Saturday was 12°C. What was the difference between the lowest temperatures?
6. Unknown number
I think the number. I'll reduce it to its one-third. The result is then increased by one-third, and I get the number 12.
7. To improper fraction
Change mixed number to improper fraction a) 1 2/15 b) -2 15/17
8. GP members
The geometric sequence has 10 members. The last two members are 2 and -1. Which member is -1/16?
9. If you
If you travel to work 22 days and it takes 29.2 minutes, how many minutes will it take to travel to work and back?
10. Difference in temperatures
The temperature in the number line show minus 15 degree celsius and 8 degree celsius. What is the different between the temperatures?
11. Expression
Solve for a specified variable: P=a+4b+3c, for a
12. Intersections
Find the intersections of the function plot with coordinate axes: f (x): y = x + 3/5
13. A man
A man spends 5/9 of his money on rent, and 5/16 of the remainder on electricity. If the final balance remaining is 550 find how much was spent on rent
14. Rectangle area
The length of a rectangle of x units is increased by 10% and its width of y units is increased by 15%. What is the ratio of the area of the old rectangle to the area if the new rectangle?
15. Water 31
Richard takes 3 1/6 liters of water before noon and 2 3/5 liters of water after noon. How many litres of water does Richard consume a day ?
16. Regrouping
Subtract mixed number with regrouping: 11 17/20- 6 19/20
17. Melting point
The melting point of mercury is -36°F and its boiling point is 672°F. What is the difference between the boiling point and the melting point?
18. Annual pension
Calculate the amount of money generating an annual pension of EUR 1000, payable at the end of the year and for a period of 10 years, shall be inserted into the bank to account with an annual interest rate of 2%
19. Two angles
The triangles ABC and A'B'C 'are similar. In the ABC triangle, the two angles are 25° and 65°. Explain why in the triangle A'B'C 'is the sum of two angles of 90 degrees.
20. Intercept with axis
F(x)=log(x+4)-2, what is the x intercept

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