Mathematics 2018 Past Questions | WAEC
Study the following Mathematics past questions and answers for JAMB, WAEC NECO and Post-JAMB. Get prepared with official past questions and answers for upcoming examinations.
21.The total surface area of a hemispher is 75\(\pi cm^2\). Find the radius.
- A. 5.0 cm
- B. 7.0 cm
- C. 8.5 cm
- D. 12.0 cm
22. Find the value of x for which \(\frac{x – 5}{x(x – 1)}\) is defined
- A. 0 or 5
- B. -5 or 5
- C. -11 or 5
- D. 0 or 1
- A. x = \(\frac{-3}{2}\) or 2
- B. x = -2 or \(\frac{3}{2}\)
- C. x = -3 or 2
- D. x = 3 or -2
24. Factorise completely the expression
\((x + 2)^2\) – \((2x + 1)^2\)
- A. (3x + 2)(1 – x)
- B. (3x + 2)(2x + 1)
- C. 3\((x + 2)^2\)
- D. 3(x + 1)(1 – x)
25. Find the \(n^{th}\) term of the sequence 2 x 3, 4 x 6, 8 x 9, 16 x 12…
- A. 2\(^n\) x 3(n + 1)
- B. 2\(^n\) x 3n
- C. 2\(^n\) x 3\(^n\)
- D. 2\(^n\) x 3\(^n – 1\)
26. If 3x\(^o\) 4(mod 5), find the least value of x
- A. 1
- B. 2
- C. 3
- D. 4
27. Find the inter-quartile range of 1, 3, 4, 5, 8, 9, 10, 11, 12, 14, 16
- A. 6
- B. 7
- C. 8
- D. 9
28. If x : y = \(\frac{1}{4} : \frac{3}{8}\) and y : z = \(\frac{1}{3} : \frac{4}{9}\), find x : z
- A. 2:3
- B. 3:4
- C. 3:8
- D. 1:2
29. Expression 0.612 in the form \(\frac{x}{y}\), where x and y are integers and y \(\neq\) 0
- A. \(\frac{153}{250}\)
- B. \(\frac{68}{111}\)
- C. \(\frac{61}{100}\)
- D. \(\frac{21}{33}\)
30. The angle of elevation of the top of a tree from a point 27m away and on the same horizontal ground as the foot of the tree is 30\(^o\). Find the height of the tree.
- A. 27m
- B. 13.5 \(\sqrt{3m}\)
- C. 13.5 \(\sqrt{2m}\)
- D. 9\(\sqrt{3m}\)
