Mathematics Past Questions and Answers

Given that the mean of the scores 15, 21, 17, 26, 18 and 29 is 21, calculate the standard deviation of the scores

A \(\sqrt{10}\)
B 4
C 5
D \(\sqrt{30}\)

Question 3767:

A bag contains 4 red and 6 black balls of the same size. If the balls are shuffled briskly and two balls are drawn one after the other without replacement, find the probability of picking balls of different colours

A \(\frac{8}{15}\)
B \(\frac{13}{25}\)
C \(\frac{11}{15}\)
D \(\frac{13}{15}\)

Question 3768:

Which of these statements about y = 8\(\sqrt{m}\) is correct?

A Log y = log 8 x log \(\sqrt{m}\)
B Log y = 3 log 2 x \(\frac{1}{2}\) log m
C Log y = 3 log 2 - \(\frac{1}{2}\) log m
D Log y = 3 log 2 + \(\frac{1}{2}\) log m

Question 3769:

If x + 0.4y = 3 and y = \(\frac{1}{2}\)x, find the value of (x + y)

A 1\(\frac{1}{4}\)
B 2\(\frac{1}{2}\)
C 3\(\frac{3}{4}\)
D 5

Question 3770:

Express 3 - [\(\frac{x - y}{y}\)] as a single fraction

A \(\frac{3xy}{y}\)
B \(\frac{x - 4y}{y}\)
C \(\frac{4y - x}{y}\)
D 3 - \(\frac{x - y}{y}\)