Year : 
1999
Title : 
Mathematics (Core)
Exam : 
JAMB Exam

Paper 1 | Objectives

31 - 40 of 45 Questions

# Question Ans
31.

The shaded portion in the graph above is represented by

A. y + x - x3 ≥ 0, y - x ≤ 0

B. y - x + x3 ≥ 0, y - x ≤ 0

C. y + x - x3 ≤ 0, y + x ≥ 0

D. y - x + x3 ≤ 0, y + x ≥ 0

Detailed Solution

y + x - x2 ≥ 0
y = x3 - x
on x axis, y = 0
∴x2 - x = 0
x(x2 - 1) = 0
x = 0 or x2 - 1 = 0
x2 = 1
x = +/-1
∴ x = -1, 0 and 1 which are the roots of the equation y + x - x2 ≥ 0
Also y - x ≤ 0
=> y ≤ 0 + x
∴ the region where y ≤ 0
32.

Find the length XZ in the triangle above.

A. √7 m

B. √6 m

C. √5 m

D. √3 m

Detailed Solution

XY2 = XY2 + Y2 - 2XY.YZ cos 120
XZ2 = 22 + 12 - 2 x 2 1 cos 120
= 4 + 1 -2 x 2 x 1 x -cos(180 - 120)
= 4 + 1 + 4 cos 60
= 5 + 4 x 1/2
= 5 + 2
= 7
XY = √7 m
33.

In the figure above, PQRS is a circle with ST//RQ. Find the value of x PT = PS.

A. 70o

B. 55o

C. 40o

D. 35o

Detailed Solution

PQRS is a cyclic quad
^P = 180 - 110 (opp ∠s of a cyclic quad)
^P = 70
In ΔPTS, ^S = ^T (base ∠s of Isc Δ)
^T = (180-70) / 2
= 110/2
= 55o
But ^T x(corr ∠)
∴x =55
34.

In the diagram above, EFGH is a cyclic quadrilateral in which EH//FG, EG and FH are chords. If ∠FHG = 42o and ∠EFH = 34o, calculate ∠HEG

A. 34o

B. 42o

C. 52o

D. 76o

Detailed Solution

∠EFH = ∠EGH(∠s in same segment)
= 34o
∠HEG = ∠HFG(∠s in same segment)
= X
also ∠HFG = ∠EHF (alternate ∠s)
But ∠EHG + ∠EFG =180(opp sof a cyclic quad)
42 + x + 34 + x = 180
2x + 76 = 180
2x = 180 - 76
2x = 104
x = 52o
35.

In the figure above, TZ is tangent to the circle QPZ. Find x if TZ = 6 units and PQ = 9 units

A. 3

B. 4

C. 5

D. 6

Detailed Solution

62 = 9 x χ
36 = 9χ
χ = 36/9
χ = 4
36.

Find the value of l in the frustrum above

A. 5cm

B. 6cm

C. 7cm

D. 8cm

Detailed Solution

ΔABE and ΔACD are similar
x
=3
6
x+4

6x = 3(x+4)
6
37.

The diagram above is the graph of y = x2, the shaded area is

A. 64 square units

B. 128/3 square units

C. 64/3 square units

D. 32 square units

Detailed Solution

\(\int_0 ^4 x^2 dx = \left[\frac{1}{3}x^2+C\right]_0 ^4\\
=\frac{1}{3}\times 4^3 - \frac{1}{3}\times 0^3\\
=\frac{64}{3}-0\\
=\frac{64}{3}\)sq units
38.

The table above shows the frequency distribution of the ages (in years) of pupils in a certain secondary school. What percentage of the total number of pupils is over 15 years but less than 21 years?

A. 35%

B. 45%

C. 50%

D. 60%

Detailed Solution

% of those above 15 but less than 21 years
age = 25/50 x 100/1
= 50%
39.

The shaded portion in the graph is represented by

A. y + x - x \(\leq\) 0, y - x \(\leq\) 0

B. y - x + x, 3 \(\leq\) 0, y - x \(\geq\) 0

C. y + x - 3 \(\geq\) 0, y + x \(\leq\) 0

D. y - x + x3 \(\geq\) 0, y + x \(\leq\) 0

C

40.

In the diagram, EFGH is a cyclic quadrilateral in which EH || FG, EG and FH are chords. If < FHG = 424o and < EFH = 34o

A. 34o

B. 42o

C. 52o

D. 76o

Detailed Solution

< EFH = < EGH = 34o (angles n the same segment)

< GHF = < GEF = 42o(angles in the same segment)

< FOG = 42 + 34 = 76(exterior angle)

< FOG = < EOH = 76(vertically opposite angle)

< EDO = 90o, < DOE = \(\frac{76}{2}\) = 38o

< HEG = 90o - 38o = 52o
31.

The shaded portion in the graph above is represented by

A. y + x - x3 ≥ 0, y - x ≤ 0

B. y - x + x3 ≥ 0, y - x ≤ 0

C. y + x - x3 ≤ 0, y + x ≥ 0

D. y - x + x3 ≤ 0, y + x ≥ 0

Detailed Solution

y + x - x2 ≥ 0
y = x3 - x
on x axis, y = 0
∴x2 - x = 0
x(x2 - 1) = 0
x = 0 or x2 - 1 = 0
x2 = 1
x = +/-1
∴ x = -1, 0 and 1 which are the roots of the equation y + x - x2 ≥ 0
Also y - x ≤ 0
=> y ≤ 0 + x
∴ the region where y ≤ 0
32.

Find the length XZ in the triangle above.

A. √7 m

B. √6 m

C. √5 m

D. √3 m

Detailed Solution

XY2 = XY2 + Y2 - 2XY.YZ cos 120
XZ2 = 22 + 12 - 2 x 2 1 cos 120
= 4 + 1 -2 x 2 x 1 x -cos(180 - 120)
= 4 + 1 + 4 cos 60
= 5 + 4 x 1/2
= 5 + 2
= 7
XY = √7 m
33.

In the figure above, PQRS is a circle with ST//RQ. Find the value of x PT = PS.

A. 70o

B. 55o

C. 40o

D. 35o

Detailed Solution

PQRS is a cyclic quad
^P = 180 - 110 (opp ∠s of a cyclic quad)
^P = 70
In ΔPTS, ^S = ^T (base ∠s of Isc Δ)
^T = (180-70) / 2
= 110/2
= 55o
But ^T x(corr ∠)
∴x =55
34.

In the diagram above, EFGH is a cyclic quadrilateral in which EH//FG, EG and FH are chords. If ∠FHG = 42o and ∠EFH = 34o, calculate ∠HEG

A. 34o

B. 42o

C. 52o

D. 76o

Detailed Solution

∠EFH = ∠EGH(∠s in same segment)
= 34o
∠HEG = ∠HFG(∠s in same segment)
= X
also ∠HFG = ∠EHF (alternate ∠s)
But ∠EHG + ∠EFG =180(opp sof a cyclic quad)
42 + x + 34 + x = 180
2x + 76 = 180
2x = 180 - 76
2x = 104
x = 52o
35.

In the figure above, TZ is tangent to the circle QPZ. Find x if TZ = 6 units and PQ = 9 units

A. 3

B. 4

C. 5

D. 6

Detailed Solution

62 = 9 x χ
36 = 9χ
χ = 36/9
χ = 4
36.

Find the value of l in the frustrum above

A. 5cm

B. 6cm

C. 7cm

D. 8cm

Detailed Solution

ΔABE and ΔACD are similar
x
=3
6
x+4

6x = 3(x+4)
6
37.

The diagram above is the graph of y = x2, the shaded area is

A. 64 square units

B. 128/3 square units

C. 64/3 square units

D. 32 square units

Detailed Solution

\(\int_0 ^4 x^2 dx = \left[\frac{1}{3}x^2+C\right]_0 ^4\\
=\frac{1}{3}\times 4^3 - \frac{1}{3}\times 0^3\\
=\frac{64}{3}-0\\
=\frac{64}{3}\)sq units
38.

The table above shows the frequency distribution of the ages (in years) of pupils in a certain secondary school. What percentage of the total number of pupils is over 15 years but less than 21 years?

A. 35%

B. 45%

C. 50%

D. 60%

Detailed Solution

% of those above 15 but less than 21 years
age = 25/50 x 100/1
= 50%
39.

The shaded portion in the graph is represented by

A. y + x - x \(\leq\) 0, y - x \(\leq\) 0

B. y - x + x, 3 \(\leq\) 0, y - x \(\geq\) 0

C. y + x - 3 \(\geq\) 0, y + x \(\leq\) 0

D. y - x + x3 \(\geq\) 0, y + x \(\leq\) 0

C

40.

In the diagram, EFGH is a cyclic quadrilateral in which EH || FG, EG and FH are chords. If < FHG = 424o and < EFH = 34o

A. 34o

B. 42o

C. 52o

D. 76o

Detailed Solution

< EFH = < EGH = 34o (angles n the same segment)

< GHF = < GEF = 42o(angles in the same segment)

< FOG = 42 + 34 = 76(exterior angle)

< FOG = < EOH = 76(vertically opposite angle)

< EDO = 90o, < DOE = \(\frac{76}{2}\) = 38o

< HEG = 90o - 38o = 52o