Question 5 - A-Level Maths

Exam Board	OCR MEI
Module	S1 (Statistics 1)
Year	2005
Session	June
Topic	Probability Definitions
Type	Listing outcomes and counting

On the insert, complete the table giving the lowest common multiples of all pairs of integers between 1 and 6 .
[0pt] [1]
\multirow{2}{*}{} Second integer
1 2 3 4 5 6
\multirow{6}{*}{First integer} 1 1 2 3 4 5 6
2 2 2 6 4 10 6
3 3 6 3 12 15 6
4 4 4 12 12
5 5 10 15
6 6 6 6 12
Two fair dice are thrown and the lowest common multiple of the two scores is found.
Use the table to find the probabilities of the following events.
(A) The lowest common multiple is greater than 6 .
(B) The lowest common multiple is a multiple of 5 .
(C) The lowest common multiple is both greater than 6 and a multiple of 5 .
Use your answers to part (ii) to show that the events "the lowest common multiple is greater than 6 " and "the lowest common multiple is a multiple of 5 " are not independent.