Foundation November 2020 Paper 2 Q17

OCRFoundationCurrent spec5 marksMultiple Events

17 Dora has the following number cards.

2 2 3 5 6

She takes a card at random, replaces the card and then takes a second card.
She adds the numbers on the two cards she has taken and records the total.

(a) Complete the following table to show all of her possible totals.

		First card
Total		2	2	3	5	6
Second card	2	4	4	5	7	8
	2	4	4	5		8
	3	5	5		8	9
	5	7		8	10	11
	6	8	8	9	11	12

[1]

(b) Find the probability that her total is

(i) an even number, [2]

(ii) a multiple of 3 or 4. [2]

Answer	Marks	Part marks and guidance
Correctly completes table	1

	First card
Total	2	2	3	5	6
Second card	2	4	4	5	7	8
2	4	4	5	7	8
3	5	5	6	8	9
5	7	7	8	10	11
6	8	8	9	11	12

Mark scheme (b)

Answer	Marks	Part marks and guidance
(i) \(\dfrac{13}{25}\) oe	2	B1FT for their correct numerator B1 for fraction with denominator 25	In (b)(i) and (ii), not ratio or words, isw eg \(\dfrac{13}{25}\), likely but not \(\dfrac{13}{25}\), unlikely isw cancelling/conversion to other forms FT numerator 12 + any evens in their (a)
(ii) \(\dfrac{14}{25}\) oe	2	FT their correct numerator / 25 B1FT for their correct numerator but denominator incorrect	FT numerator 13 + any multiples of 3 or 4 in their (a)

Answer