Past papers › JAMB 2001 · UME › Question 49 Question JAMB General Maths 2001 Objective Probability Probability
The distribution of colours of beads in a bowl is: blue 1, black 2, yellow 4, white 5, brown 3. What is the probability that a bead selected at random will be blue or white?
A 1 15 \frac1{15} 15 1 B 1 3 \frac13 3 1 C 2 5 \frac25 5 2 D 7 15 \frac7{15} 15 7
Worked solution (try it first) There are
1 + 2 + 4 + 5 + 3 = 15 1 + 2 + 4 + 5 + 3 = 15 1 + 2 + 4 + 5 + 3 = 15 beads.
Blue or white is
1 + 5 = 6 1 + 5 = 6 1 + 5 = 6 beads.
So the probability is
6 15 = 2 5 \frac{6}{15} = \frac25 15 6 = 5 2 , option C.
Watch out
"Blue or white" includes both colours. Using only the white beads gives 5 15 = 1 3 \frac{5}{15} = \frac13 15 5 = 3 1 Report a problem with this question