## 10 March 2011

### DIRECTED NUMBERS & SQUARE, SQUARE ROOT, CUBES AND CUBE ROOTS TEST

1. Which of the following has a positive value?
A. – 8 x (– 9)
B. – 13 x 2
C. – 156 ÷ 13
D. 120 ÷ (– 8)

2. 7 x (– 8) =
A. 28
B. –56
C. –54
D. 56

3. In a certain experiment, the initial temperature of a chemical solution is 25ºC. The solution is then put into cold water to cool at rate of 4ºC every minute for 8 minutes. After that, it is heated at a rate of 3ºC every minute for 5 minutes. Find the final temperature, in ºC, of the solution.
A. – 72
B. – 22
C. 8
D. 42

4. Evaluate 180 + 48 ÷ (– 6) x 4.
A. 148
B. 152
C. 182
D. 212

5. Which of the following numbers is NOT a perfect square?
A. 9
B. 169
C. 49
D. 329

6. Which of the following is arranged in descending order?
A. –8.26, –9.16, 0.96, 2.76
B. –1.060, –1.600, –2.600,2.606
C. –3.45, –3.54, –3.15, –3.65
D. 2.01, 3.02, 4.03, 5.05

7. The volume of a cube is 125 cm³. Calculate the total surface area, in cm², of the cube.
A. 60
B. 100
C. 150
D. 750

8. The cube of ( 1 – 3 ) is
A. – 2
B. 2
C. – 8
D. 8

9. The area of a square is 49 m². Find the length in m, of each side.
A. 25.5
B. 7
C. 17
D. 28

10. Calculate the result of adding all the perfect cubes between 10 and 100.
A. 27
B. 64
C. 91
D. 92

11. In winter, the room temperature of a house has been pre-heated to 10ºC. Outside the house the temperature is – 12 ºC. what is the difference in temperature between the two places?
A. 22ºC
B. 2ºC
C. 20ºC
D. 24ºC

12. The volume of a cube is 3.375 cm³. What is the length, in cm, of its side?
A. 1.5
B. 3.5
C. 15
D. 0.15

13. Which of the following is not a perfect square?
A. 81
B. 48
C. 225
D. 169

14. The approximate value of 6.35² lies between
A. 30 and 36
B. 36 and 49
C. 30 and 49
D. 30 and 40

15. The square of x is 64 and the cube of y is 125. Find the value of x + y.
A. 8
B. 5
C. 13
D. 40

16. A lift at the 15th floor goes down 7 floors. If the lift goes down 4 more floors and then rises 9 floors, at which floor is the lift now?
A. 13
B. 21
C. 15
D. 27

17. 47 – ( – 13 ) + ( – 18 ) =
A. – 32
B. 16
C. 42
D. 78