O-LevelMathematicsProbability4024/22 · Oct/Nov 2024 · Q56 Marks
Mandeep has these 9 number cards. 1 1 2 2 2 5 6 7 8
- (a)She takes one of the 9 cards at random, notes the number and replaces it. Find the probability that the card shows an odd number.[1]
- (b)Mandeep takes one of the 9 cards at random, notes the number and replaces it. She then takes a second card at random. Find the probability that both cards show the number 1.[2]
- (c)Mandeep takes two of the 9 cards at random without replacement. She calculates the product of the two numbers shown. Find the probability that the product is less than 5.[3]
Mark scheme
Marking points from the official mark scheme (Oct/Nov 2024). The mark or mark type is shown in brackets.
- [1] 4/9 oe
- [2] 4/81 oe
- [M1] for 2/9 × 2/9 oe
- [3] 5/18 oe
- [M2] for (2/9 × 1/8) + (3/9 × 2/8) + (2/9 × 2/8) oe
- [M1] for (k/9 × (k-1)/8) where k = 2, 3, 4 or 5 oe seen
- [M1] for combinations 1 × 1, 1 × 2, 2 × 1 and 2 × 2 identified
- [SC1] if 0 scored, for answer 25/81
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →