4MA0 Foundation January 2014 Paper 1R Q13
13 Morse Code uses dots (●) and dashes (▬) to represent each letter of the alphabet.
Here are 10 cards.
Each card has the Morse Code for a letter on it.
(a) Kelly has the 10 cards.
She takes at random one of the cards.
Find the probability that she takes a card with
She takes at random one of the cards.
Find the probability that she takes a card with
(i) 4 dots,
(ii) exactly 1 dot,
(iii) 2 dots or 3 dots.
(5)(b) Hashim has the 10 cards.
He takes at random a card 200 times.
He replaces the card each time.
Work out an estimate for the number of times he will take a card with exactly 2 dots. (2)
He takes at random a card 200 times.
He replaces the card each time.
Work out an estimate for the number of times he will take a card with exactly 2 dots. (2)
| Scheme | Marks |
|---|---|
| (i) Answer: 0 | B1 |
(ii) Answer: \(\dfrac{3}{10}\) | M1 A1 |
| (iii) \(\dfrac{4}{10} + \dfrac{2}{10}\) or 4 + 2 or 6 | M1 |
| \(\dfrac{6}{10}\) or \(\dfrac{3}{5}\) | A1 |
| (5) |
Notes
B1: Also accept \(\dfrac{0}{1}\), \(\dfrac{0}{10}\)
M1
A1: = denominator of 10
= numerator of 3
| Scheme | Marks |
|---|---|
| eg \(\dfrac{4}{10} \times 200\) | M1 |
| 80 | A1 |
| (2) | |
| (Total 7 marks) |
Notes
A1: cao