EduNinja

[Maximum number: 3]

The 200 students also estimate the total area, $A \mathrm{~m}^{2}$ , of the windows in the classroom. The table shows their results.

Table for Question 1 — CAIE IGCSE Mathematics Extended

Two students are chosen at random from those students that estimated the area of the windows to be more than $100 \mathrm{~m}^{2}$ .

Find the probability that one of the two students estimates the area to be greater than $150 \mathrm{~m}^{2}$ and the other student estimates the area to be $150 \mathrm{~m}^{2}$ or less.

$\frac{3840}{10712}$ oe isw $\left[\frac{480}{1339}\right]$
M2 for $[2\times]\left(\frac{24}{104}\times\frac{80}{103}\right)$ oe, or M1 for $\frac{24}{104},\frac{80}{103}$ seen.

[Maximum number: 5]

(a)

Figure for Question (a) — CAIE IGCSE Mathematics Extended

The diagram shows 11 cards.

[ 3 ]

(i)

A card is chosen at random from these 11 cards and then replaced.
A second card is then chosen at random.
Find the probability that exactly one card has the letter N.

[ 3 ]

$\frac{36}{121}$ oe
M2 for $2\times\frac2{11}\times\frac9{11}$ oe
or M1 for $\frac2{11}\times\frac9{11}$ oe
If 0 scored, SC1 for $\frac{36}{110}$

(b)

Figure for Question (b) — CAIE IGCSE Mathematics Extended

50 students are asked if they like English ( E ) and if they like mathematics ( M ). 3 say they do not like English and do not like mathematics.
33 say they like English.
42 say they like mathematics.

[ 2 ]

(i)

Two students are chosen at random.

Find the probability that they both like mathematics.

[ 2 ]

$\frac{123}{175}$ oe
M1 for $\frac{42}{50}\times\frac{41}{49}$

[Maximum number: 2]

The speed, $v \mathrm{~km} / \mathrm{h}$ , of each of 200 cars passing a building is measured. The table shows the results.

Table for Question 3 — CAIE IGCSE Mathematics Extended

Two of the 200 cars are chosen at random.

Find the probability that they both have a speed greater than $50 \mathrm{~km} / \mathrm{h}$ .

$\frac{87}{3980}$ oe
M1 for $\frac{30}{200}\times\frac{29}{199}$ .

CAIE IGCSE Mathematics Extended E8.3 Probability of Combined Events Topic Practice

Question 1

Question 2

Question (a)

Question (i)

Question (b)

Question (i)

Question 3