# Mathematics 2021 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.

31. A trapezium of sides 10cm and 21cm and height 8cm is inscribed in a circle of radius 7cm, calculate the area of the region not covered by the trapezium (take π=22/7)

- A. 84cm
^{2} - B. 80cm
^{2} - C. 30cm
^{2} - D. 94cm
^{2}

**Correct Option: Answer is C**

Area of circle – Area of Trapezium

Area of Circle = A = π r²

Area of Trapezium = ½ × (a + b) × h

22/7 x 7 x 7 – ½ × (10 + 21) × 8

= 154 – 124 =30cm^{2}

**32. **Find, correct to two decimal places, the mean of 1 1/2, 2 2/3, 3 3/4, 4 4/5 and 5 5/6

- A. 3.71
- B. 3.70
- C. 3.69
- D. 3.72

**Correct Option: Answer is B**

1.5+2.67+3.75+4.8+5.58 =18.3/5 =3.66 =3.70 to 2.d.p

**33. ****A **cyclist moved at a speed of X *km/h *for 2 He then increased his speed by 2 *km/h* for the next 3 *hours. *If the total distance covered is 36 *km, *calculate his initial speed, *X*

- A. 12km/h
- B. 3km/h
- C. 3km/h
- D.6km/h

**Correct Option: Answer is C**

2\(^\sqrt{2x+1}\) = 32 ;

2\(^\sqrt{2x+1}\) = 2\(^5\)

\(\sqrt{2x+1}\) = 5

2x+1 =5^{2}

2x+1=25; 2x =25-1

2x =24; x =12

**34. **Find the value of (x+y) in the diagram

- A. 215
^{o} - B.
^{70o} - C. 135
^{o} - D.
^{145o}

**Correct Option: Answer is D**

= 110 +35 =145^{o}

**35. **In the diagram, *MP *is a tangent to the circle *NQR, /PNQ=* 64^{o} and |RQ| = |RN find the angle marked x.

**A.**22**B.**24**C.**36**D.**26

**Correct Option: Answer is D**

**36. **find the first quartile of 8, 7, 9, 11, 8 7, 9, 6 and 8

**A.**8.5**B.**7.0**C.**7.5**D.**8.0

**Correct Option: Answer is B**

6,7,7,7,8,8,8,9,9,11

Q1 =7 + 7= 14/2 =7

**37. **In the diagram, PQRS is a circle, find the value of x.

**A.**50^{o}**B.**50^{o}**C.**80^{o}**D.**50^{o}

**Correct Option: Answer is **

**38. **A cone has a base radius of 8cm and height 11cm. calculate, correct to two decimal places, the curved surface area. Take π=22/7

**A.**341.98cm^{2}**B.**276.57cm^{2}**C.**201.14cm^{2}**D.**477.71cm^{2}

**Correct Option: Answer is B**

Curve surface area = πrl

=22/7 x 8 x 11 = 276.57cm^{2}

**39. **Given that sin x =3/5, 0<x<90^{o}, evaluate (tan x +2 cos x)

**A.**2 11/20**B.**2 7/20**C.**11/20**D.**1/20

**Correct Option: Answer is B**

Sinx = 3/5; cosx =4/5; tanx = ¾

Therefore, (tan x +2 cos x)

= ¾ + 2 x 4/5 = ¾ + 8/5 = 15+32/20 =47/20 = 2 7/20

**40. **In the diagram, *EC* is a diameter of the circle *ABCDE.* If angle AB*C=* 158^{o} find* angle ADE.*

**A.**112^{o}**B. 90**^{o}**C. 68**^{o}**D.**22^{o}

**Correct Option: Answer is C**

**41. **

Height ()cm | 160 | 161 | 162 | 163 | 164 | 165 |

No of Player | 4 | 6 | 3 | 7 | 8 | 9 |

The table shows the heights of thirty seven players of a basketball team. Calculate, correct to one decimal place the mean height of the player

**A.**163.0**B.**162**C.0**160.5**D.**165.0

**Correct Option: Answer is A**

Height (x) | No of Players (f) | fx |

160 | 4 | 640 |

161 | 6 | 966 |

162 | 3 | 486 |

163 | 7 | 1141 |

164 | 8 | 1312 |

165 | 9 | 1485 |

| 37 | 6030 |

Mean height = 6030/37 =163 2.d,p

**42. **XY is a line segment with the coordinates X(-8,-12) and Y(p,q). if the midpoint of XY is (-4, -2) find the coordinates of Y

**A.**(-6,-10)**B.**(0,8)**C.**(4,10)**D.**(0,4)

**Correct Option: Answer is B**

x_{1}= -8; x_{2} = p, y_{1}= -12; y_{2} =q

midpoint = x1 + x2/2 ; y1 + y2/2

-4= -8+p/2; -2 = -12+q/2

-8= -8 + p; p =0

-4= -12 + q; q= 8

Therefore, coordinate of Y is (0, 8)

**43. **Five hundred tickets were sold for a concert. Tickets for adults and children were sold at $4.50 and $3.00 respectively. If the total receipts for the concert was $ 1,987 50, how many tickets for adults were sold?

**A.**325**B.**235**C.**175**D.**400

**Correct Option: Answer is A**

Adult = a; Children =c

Total receipts sold = 4.5a + 3c =1987.5

Total ticket = a + c = 500

4.5a + 3c =1987.5 x 1

a + c = 500 x 4.5

4.5a + 3c =1987.5

__4.5a + 4.5c = 2250__

1.5c = 262.5/1.5

C = =175 ticket sold for children, while 500 -175= 325 ticket sold for Adults

**44. **The distance (d) between two villages is more than 18 km but not more than 23 km Which of these inequalities represents the statement?

**A.**18≤d≤23**B.**18<d<23**C.**18≤d<23**D.**18<d≤23

**Correct Option: Answer is B**

**45. **The pie chart represents the distribution of fruits on display in a shop. If there are 60 apples on display, how many oranges are there?

**A.**80**B.**270**C.**120**D.**90

**Correct Option: Answer is D**

Let x represents total of fruit in display

Apples has 60 apples

=80/360 x X =60; 80/360 = 60; x =270

So orange = 120/360 x 270 =90