Question : The optimum dissolved oxygen level ( in mg / litre ) required for survival of aquatic organisms is:

Option 1: 4 - 6

Option 2: 2 - 4

Option 3: 8 - 10

Option 4: 12 - 16

Question : If $(4 y-\frac{4}{y})=13$, find the value of $(y^2+\frac{1}{y^2})$.

Option 1: $12 \frac{11}{16}$

Option 2: $10 \frac{9}{16}$

Option 3: $12 \frac{9}{16}$

Option 4: $8 \frac{9}{16}$

Question : The value of $4 \div 12$ of $[3 \div 4$ of $\{(4-2) \times 6 \div 2\}]-2 \times 6 \div 8+3$ is:

Option 1: $4 \frac{1}{6}$

Option 2: $3 \frac{1}{3}$

Option 3: $2 \frac{1}{3}$

Option 4: $7 \frac{1}{6}$

Question : The value of $\sqrt{9+2\sqrt{16}+\sqrt[3]{512}}$ is:

Option 1: 6

Option 2: 5

Option 3: $\sqrt[2]{8}$

Option 4: $\sqrt[3]{6}$

Question : The diagonals of a rhombus are 12 cm and 16 cm, respectively. The length of one side is:

Option 1: 8 cm

Option 2: 6 cm

Option 3: 10 cm

Option 4: 12 cm

Question : Directions: By interchanging the given two signs which of the following equations will be not correct?
– and ×

Option 1: 20 × 12 + 6 – 16 ÷ 8 = 20

Option 2: 16 × 91 ÷ 13 + 5 – 3 = 24

Option 3: 20 × 8 – 4 ÷ 2 + 3 = 7

Option 4: 4 × 5 – 36 ÷ 6 + 10 = 10