WAEC Mathematics Maths Questions 2021

WAEC Mathematics Maths Questions

2021 1. Which of these numbers is not less than -2? -1, -3, -4, -5. -6 Solution Solving: -2 is greater than -2, -3, -4, -5, -6 and so on. But -1 is greater than -2. The Correct Answer is A): Because it is greater than -2. 2. -6

is greater than -2 but less than -7? True or false True Both False None of the above Solving for the solution: -6 is greater than any number from -7 to the negative infinity but less than any number from -5 to the positive infinity. The Correct Answer is C): Because -6 is not greater than -2 and it is not less than -7. 3. Add 26b + 12a + 16a – 4b 22b + 28a -22b + 28a 22b – 28a -22b – 28a Solution Solving for Questions 3: Firstly, you have to Collect like terms. Therefore, we have; 26b – 4b + 12a + 16a. Next, we have 26b – 4b = 22b And 12a + 16a = 28a Therefore, we have 22b + 28a The Correct Answer is A): 22b + 28a 4. Multiply this equation: (x – 6)(2x + 7)? 2×2 + 5x – 42 2×2 – 5x – 422×2–5x+422×2+5x+42-2×2+ 5x – 42 Solving for question 4 solution: Here, we start by removing the bracket Thus; 2×2 + 7x – 12x – 42 Hence, 2×2 – 5x – 42 The Correct Answer is B): 2×2 – 5x – 42 5. Factorise the following: 5×2 – 15x – 20? 5(x+4)(x+1). -2(x-4)(x+5) -5(x+4)(x-1) 5(x-4)(x+1) Solution Solving to question 5: Firs find the L.C.M of 5, 15 and 20 = 5(x2 – 3x – 4). = 5(x2 – 4x + x – 4). = 5{x(x – 4) +1(x – 4)}. = 5(x-4)(x+1). The Correct Answer is D): 5(x-4)(x+1) Answer any … questions. Write your answers on the answer booklet provided. 1. A sector of a circle with a radius of 21 cm has an area of 280 cm². (a) Calculate, correct to 1 decimal place, the perimeter of the sector. (b) If the sector is bent such that its straight edges coincide to form a cone, calculate, correct to the nearest degree, the vertical angle of the cone.

2. (a) Solve the equation: (b) In the diagram, < STQ = m , < TUQ = 800, < UPQ = r , < PQU = n and < RQT = 880. Find the value of (m + n ).3.A={2,4, 6,8},B={2,3,7,9}andC={x:3

N6.50 per square meter, leaving a margin of 2m wide along the longer sides; (c) percentage of the part not cleared. 10. Two fair dice are thrown. M is the event described by “the sum of the scores is 10” and N is the event described by “the difference between the scores is 3”. (a) Write out the elements of M and N. (b) Find the probability of M or N. (c) Are M and N mutually exclusive? Give reasons. 11. (a) The total surface area of two spheres is in the ratio of 9:49. If the radius of the smaller sphere is 12 cm, find, correct to the nearest cm3, the volume of the bigger sphere. (b) A cyclist starts from a point X and rides 3 km due West to a point Y. At Y, he changes direction and rides 5 km North-West to a point Z. (i) How far is he from the starting point, correct to the nearest km? (ii) Find the bearing of Z from X, to the nearest degree. 12. 13. (a) If, find x in terms of y. (b) The table shows the distribution of timber production in five Nigerian states in a certain year. Community Timber Production (tonnes) Cross River Delta Edo Ogun Ondo 600 900 1800 1500 2400 (i) Draw a pie chart to represent the information. (ii) What percentage of timber produced that year was from Delta? (iii) If a tonne of timber is sold at N560.00, how much more revenue would Edo state receive than Cross River? Objective Answer ALL questions in this section. Shade your answer in the answer booklet provided.

1. In a school, 180 students offer mathematics or physics or both. If 125 offer mathematics and 105 offer physics. How many students offer mathematics only? A.75 B. 80 C. 55 D. 125. 2. Find the value of x for which 3(24x + 3) = 96 A. 2 B. -2 C. ½ D. -1/2 3. The cost of renovating a 5m square room is N500. What is the cost of renovating a 10m square room? A. N1,000 B. N2,500 C. 2,000 D. N10,000 4. Find the rate of change of the total surface area S of a sphere with respect to its radius r when r = 2 A. 8 B. 16 C. 10 D. 14 5. Differentiate (cosӨ + sinӨ)2 with respect to Ө. A. 2cos2Ө B. 2sin2Ө C. -2cos2Ө D. -2sin2Ө 6. A binary operation * on the set of rational numbers is defined as