Students in a school are divided into two levels, Junior Level and Senior Level. There are $850$ s

Question

Students in a school are divided into two levels, Junior Level and Senior Level. There are $850$ students in Junior Level and $650$ students in Senior Level. The number of siblings that each student has are summarised in the table.

Number of Siblings
	0	1	2	$\ge 3$
Junior Level	$288$	$362$	$110$	$90$
Senior Level	$180$	$242$	$108$	$120$

A student is chosen at random from the school.

Find the probability that the student is from Senior Level and has no sibling.[1]
Find the probability that the student has at most $2$ siblings.[1]
Find the probability that the student is from Senior Level or has at most $2$ siblings but not both.[1]
Determine whether or not the events 'the student has at least $3$ siblings' and 'the student is from Junior Level' are independent.[3]

Accepted Answer

(i) $3/25$; (ii) $43/50$; (iii) $44/75$; (iv) not independent.

	0	1	2	\(\ge 3\)
Junior Level	\(288\)	\(362\)	\(110\)	\(90\)
Senior Level	\(180\)	\(242\)	\(108\)	\(120\)

2024 JPJC H1 Q6

2024 JPJC H1 Q6

Solution:

Solution locked