WAEC - Mathematics (1991)

  • 1
    Express 0.0462 in standard form
    Răspuns
    (D)
    4.62 x 10-2
  • 2
    The population of a village is 5846. Express this number to three significant figures
    Răspuns
    (A)
    5850
  • 3
    Simplify: log6 + log2 - log12
    Răspuns
    (C)
    0
  • 4
    Find the number whose logarithm to base 10 is 2.6025
    Răspuns
    (A)
    400.4
  • 5
    Simplify: \((\frac{1}{4})^{-1\frac{1}{2}}\)
    Răspuns
    (E)
    8
  • 6
    For what value of y is the expression \(\frac{y + 2}{y^{2} - 3y - 10}\) undefined?
    Răspuns
    (D)
    y = 5
  • 7
    Factorize 3a\(^2\) - 11a + 6
    Răspuns
    (A)
    (3a - 2)(a - 3)
  • 8
    Solve the equation: 3a + 10 = a\(^2\)
    Răspuns
    (E)
    a = 5 or a = -2
  • 9
    Simplify \((\frac{3}{x} - \frac{15}{2y}) \div \frac{6}{xy}\)
    Răspuns
    (A)
    \(\frac{2y - 5x}{4}\)
  • 10
    Simplify: \(\frac{1}{4}(2^n  - 2^{n + 2}\))
    Răspuns
    (A)
    \(2^{n - 2} - 2^n\)
  • 11
    Find the equation whose roots are -2/3 and -1/4
    Răspuns
    (A)
    12x2 + 11x + 2 = 0
  • 12
    Solve: 6(x - 4) + 3(x + 7) = 3
    Răspuns
    (B)
    2/3
  • 13
    If 2x + y = 7 and 3x - 2y = 3, by how much is 7x greater than 10?
    Răspuns
    (C)
    7
  • 14
    A cylinder of base radius 4cm is open at one end . If the ratio of the area of its base to that of its curved surface is 1:4, calculate the height of the cylinder
    Răspuns
    (D)
    8cm
  • 15
    A headmaster contributes 7% of his income into a fund and his wife contributes 4% of her income. If the husband earns N5,500 per annum (p.a) and the wife earns N4,000 (P.a), find the sum of their annual contribution to the fund
    Răspuns
    (C)
    N545
  • 16
    A car is travelling at an average speed of 80km/hr. Its speed in meters per second (m/s) is
    Răspuns
    (B)
    22.2m/s
  • 17
    Mrs. Kofi sold an article for C7.50 instead of C12.75. Calculate her percentage of error, correct to one decimal place.
    Răspuns
    (A)
    41.2%
  • 18

    In the diagram above, PXR and PYO are two semi-circles with diameters 14cm and 7cm respectively. Find the area of the enclosed region, PXROY correct to the nearest whole number

    Răspuns
    (A)
    96cm2
  • 19

    In the diagram above, PXR and PYO are two semicircles with diameters 14cm and 7cm respectively. Find the perimeter of the region (take \(\pi\) = \(\frac{22}{7}\) )

    Răspuns
    (C)
    40cm
  • 20
    The shaded portion shows the outer boundary
    of the half plane defined by the inequality
    Răspuns
    (A)
    4x + 3y \(\geq\) 6
  • 21

    Find the coordinates of point B

    Răspuns
    (E)
    (11/2, 0)
  • 22
    The first term a of an A.P is equal to twice the
    common difference d. Find, in terms of d, the 5th
    term of the A.P.
    Răspuns
    (C)
    6d
  • 23
    The common ratio of a G.P. is 2. If the 5th term is
    greater than the 1st term by 45, find the 5th term,
    Răspuns
    (D)
    48
  • 24
    Two towns, P and Q, are on (4oN 40oW) and (4oN
    20oE) respectively. What is the distance between
    them, along their line of latitude? (Give your
    answer in teems of π and R, the radius of the earth).
    Răspuns
    (D)
    πR/3
    cos4o
  • 25

    the graph above is a sketch of

    Răspuns
    (B)
    y=sinx
  • 26
    Given that sin \(\theta\) = -0.9063, where O \(\leq\) \(\theta\) \(\leq\) 270°, find \(\theta\).
    Răspuns
    (D)
    245o
  • 27
    From the top of a cliff, the angle of depression of
    a boat on the sea is 60o, if the top of the cliff is
    25m above the sea level, calculate the horizontal
    distance from the bottom of the cliff to the boat.
    Răspuns
    (C)
    25√3m/3
  • 28
    The angle of elevation of the top of a tree 39m
    away from a point on the ground is 30o. Find the height of the tree
    Răspuns
    (B)
    13√3m
  • 29

    In the diagram above, ATR is a tangent at the point T to the circle center O, if ∠TOB = 145°, find ∠TAO

    Răspuns
    (D)
    55o
  • 30
    P={2, 1,3, 9, 1/2}; Q = {1,21/2,3, 7} and R = {5, 4, 21/2}. Find P∪Q∪R
    Răspuns
    (E)
    (1/2, 1, 2, 21/2, 3, 4, 5, 7, 9)
  • 31
    P = {2, 1,3, 9, 1/2}; Q = {1,21/2,3, 7} and R = {5, 4, 21/2}. Find P∩Q∩R
    Răspuns
    (B)
  • 32
    In a class of 80 students, every student had to study Economics or Geography or both Economics and Geography. lf 65 students studied Economics and 50 studied Geography, how many studied both subjects?
    Răspuns
    (C)
    35
  • 33
    Which of the following is not a measure of dispersion?
    Răspuns
    (A)
    Mode
  • 34
    The mean of 30 observations recorded in an experiment is 5. lf the observed largest value of 34 is deleted, find the mean of the remaining observations
    Răspuns
    (B)
    4
  • 35

    Find the mean of the distribution

    Răspuns
    (C)
    4.4
  • 36
    Find the mode of the distribution
    Răspuns
    (D)
    5
  • 37
    No. of chairs 1 2 3 4 5 6 7
    Frequency 2 7 5 4 9 7 6

    Find the median of the distribution

    Răspuns
    (C)
    5
  • 38

    If two events are mutually exclusive, their intersection is empty. This means that there are no outcomes that are common to both events. In probability terms, if X and Y are mutually exclusive events, then:

    Pr(X ∩ Y) = 0

    Răspuns
    (A)
    0
  • 39
    If events X and Y are mutually exclusive, P(X) = 1/3 and P(Y) = 2/5, P(X∪Y) is
    Răspuns
    (D)
    11/15
  • 40
    A box contains 2 white and 3 blue identical marbles. If two marbles are picked at random, one after the other without replacement, what is the probability of picking two marbles of different colors?
    Răspuns
    (B)
    3/5
  • 41
    Mrs. Jones is expecting a baby. The probability that it will be a boy is 1/2 and probability that the baby will have blue eyes is 1/4. What is the probability that she will have a blue-eyed boy?
    Răspuns
    (A)
    1/8
  • 42
    Which of the following about a rhombus may not be true?
    Răspuns
    (A)
    The diagonals are equal
  • 43
    The angles of a pentagon are x°, 2x°, (x + 60)°, (x + 10)°, (x -10)°. Find the value of x.
    Răspuns
    (D)
    80
  • 44

    In the diagram above, ∠PTQ = ∠URP = 25° and XPU = 4URP. Calculate ∠USQ.

    Răspuns
    (D)
    130o
  • 45
    In a given regular polygon, the ratio of the exterior angle to the interior angles is 1:3. How many side has the polygon?
    Răspuns
    (D)
    8