Edexcel IGCSE Math B Number and Algebra Question Bank
Build confidence across Number, Sets, Algebra, Functions and Matrices by practising calculations, symbolic methods, graphs and transformations.
- Syllabus
- First assessment 2018
- Course
- Math B 4MB1
Build confidence across Number, Sets, Algebra, Functions and Matrices by practising calculations, symbolic methods, graphs and transformations.
The width of a rectangle is x metres.
The length of the rectangle is 8 metres longer than the width of the rectangle.
Find an expression in terms of x for the perimeter, in metres, of the rectangle.
Simplify your answer.
x+x+(x+8)+(x+8)
M1 for 4 x+16 oe Allow for a correct answer (that is not their final
answer) seen within the working
4 x+16
A1 Allow factorised forms eg 4(x+4) or 2(2 x+8)
Do not ISW
Factorise x2+8x−20.
(x+10)(x-2)
M1 Must be in the form (x+a)(x+b) and multiply out to give at
least 2 correct terms
(x+10)(x-2)
A1 ignore any subsequent solving
Hence write down the range of values of x for which the area of the rectangle is greater than 20 m2.
From part (b):
x2+8x−20=(x+10)(x−2)
For the rectangle area to be greater than 20 m2:
x2+8x>20
so
x2+8x−20>0
Final answer:
x>2
Marking notes:
Follow through their part (b) where the factorised form has only one positive critical value and only one region is given. Condone x≥2.

Ahmed and Hani play a game with 20 numbered balls.
The 20 balls are numbered from 1 to 20.
The balls are put in a bag.
Ahmed takes at random a ball from the bag, makes a note of its number and puts the ball back into the bag.
If the number is a multiple of 5, Ahmed wins.
If Ahmed does not win, Hani takes a ball, replaces it, and wins if the number is a multiple of 3.
If Hani does not win, Ahmed takes a ball, replaces it, and wins if the number is a multiple of 6.
If Ahmed does not win, Hani takes a ball, replaces it, and wins if the number is a multiple of 4.
If Hani does not win, the game stops and the result is a draw.
Write down all the multiples of 3 lying between 1 and 20.
Answer: 3,6,9,12,15,18.
Marks: B1.
15E={1,2,3,4,5,6,7,8,9}A={2,4,6,8}B={1,3,5,7,9}C={2,3,5,7}
(a) (i)
1, 2, 3, 5, 7, 9
B1
List the elements of the set
(i)
1, 2, 3, 5, 7, 9
B1
B∪C
1, 2, 3, 5, 7, 9
B1
A′∩C
3, 5, 7
B1
(A∩B)′
(3)
1, 2, 3, 4, 5, 6, 7, 8, 9
B1
Explain why A∩B∩C=∅
eg there are no elements in all three of A, B,
C
or A B= as A has even numbers and B
has odd numbers, so A B C must be
' A and B have nothing in common'
'there is nothing in common'
'there are no common elements'
ое
reason
B1


Diagrams NOT accurately drawn.
Figure 3 shows a rectangle with dimensions 20 cm by 10 cm from which a square with sides of length x cm is removed from each of the corners.
The shape in Figure 3 is then folded along the dotted lines to form a box, without a lid, in the shape of a cuboid, shown in Figure 4.
The volume of the box is Vcm3.
Find, to 3 significant figures, the value of x such that dxdV=0.
Solutions of ax2+bx+c=0 are x=2a−b±b2−4ac.
dxdV=12x2−120x+20012x2−120x+200=0x=2×12120±1202−4×12×200
Final answer:
x=2.11
Marking notes:
Allow 315−53. Do not accept 7.89.
Complete the following table of values for V=4x3−60x2+200x.

168, 96
B2

On the grid opposite, plot the points from your completed table and, using your answer to part (b), join them to form a smooth curve.
Fully correct graph.
Marking notes:
Award B2 for a fully correct graph, allowing the maximum at 1.5<x≤2.5.
Award B1 for all points plotted correctly, or 4 points plotted correctly with a curve joining all plotted points.
By drawing on the grid a tangent to the curve, find an estimate of the gradient of the curve at the point where x=1.5.
Tangent drawn at 1.5
M1 attempt to draw tangent at 1.5
40-55
A1 must see tangent drawn.
Starting with a square of side 15 cm and removing a square with sides of length x cm from each corner, a second box without a lid is formed by folding as in part (a).
The volume of this box is Bcm3, where
B=4x3−60x2+225x.
Given that B=200, find, by drawing a suitable straight line on the grid, estimates, to one decimal place, of the possible values of x.

y=200-25 x
M1 for indicating that 200-25 x is the line. Implied by correct
line drawn
line y=200-25 x drawn
A1 line through (1,175) and (4,100)
1.3, 3.9
A1 correct line must be drawn allow +/- 0.1