In a class of 45 students, 28 offer chemistry and 25 offer Biology. If each student offers at least one of the two subjects, calculate the probability that a student selected at random from the class the class offers chemistry only

• A. \(\frac{2}{9}\)
• B. \(\frac{4}{9}\)
• C. \(\frac{5}{9}\)
• D. \(\frac{7}{9}\)

The nth term of a sequence is given by (-1)\(^{n-2}\) x 2\(^{n-1}\). Find the sum of the second and third terms.

• A. -2
• B. 1
• C. 2
• D. 6

If sin x = cos 50°, then x equals

• A. 40°
• B. 45°
• C. 50°
• D. 90°

The sixth term of an A.P is half of its twelfth term. The first term of the A.P is equal to

• A. zero
• B. half of the common difference
• C. double the common difference
• D. the common difference

(a) Copy and complete the table of values for the relation \(y = 3x^{2} - 5x - 7\).

(b) Using scales of 2 cm to 1 unit on the x- axis and 2 cm to 5 units on the y- axis, draw the graph of \(y = 3x^{2} - 5x - 7, -3 \leq x \leq 4\).

(c) From the graph : (i) find the roots of the equation \(3x^{2} - 5x - 7 = 0\) ; (ii) estimate the minimum value of y ; (iii) calculate the gradient of the curve at the point x = 2.

Find the LCM of 2³ x 3 x 5², 2 x 3² x 5 and 2³ x 3³ x 5

• A. 2² x 3³ x 5²
• B. 2³ x 3³ x 5
• C. 2² x 3² x 5²
• D. 2³ x 3³ x 5²

Given that \(y = 4 - 9x\) and \(\Delta x = 0.1\), calculate \(\Delta y\).

• A. 9.0
• B. 0.9
• C. -0.3
• D. -0.9

A man with N5,000 spent 1/5 at the Chemist and ¼ at the Electric shop. How much money did he have left?

• a. N2,750
• b. N3,750
• c. N4,000
• d. N1,000

50 men can build a house in 60 days. How many more men of equal strength and ability must be put on so as to finish a similar house in 40 days?

• A. 20 men
• B. 30 men
• C. 35 men
• D. 25 men

The table shows the mark obtained by students in a test.

If the mean mark is 3, find the value of k.

• A. 4
• B. 1
• C. 2
• D. 3