Higher June 2025 Paper 1 Q15
15 The histogram gives information about the weights, in grams, of some biscuits.
One of these biscuits is taken at random.
Work out an estimate for the probability that the biscuit will have a weight between 20 grams and 40 grams. (4)
| Answer | Mark | Mark scheme |
|---|---|---|
| \(\dfrac{130}{400}\) oe | M1 | for a method to find the frequency (or area) of one relevant interval, eg \(3 \times 10\ (= 30)\) or \(5 \times 20\ (= 100)\) or \(8 \times 15\ (= 120)\) or \(10 \times 15\ (= 150)\) or \(5 \times 10\ (= 50)\) or \(8 \times 10\ (= 80)\) or, using 1 cm2 = 1 unit, \(3 \times 2\ (= 6)\) or \(5 \times 4\ (= 20)\) or \(8 \times 3\ (= 24)\) or \(10 \times 3\ (= 30)\) or \(5 \times 2\ (= 10)\) or \(8 \times 2\ (= 16)\) |
| M1 | for a method to find the total frequency (or area), eg \(\text{``}30\text{''} + \text{``}100\text{''} + \text{``}120\text{''} + \text{``}150\text{''}\ (= 400)\) or \(\text{``}6\text{''} + \text{``}20\text{''} + \text{``}24\text{''} + \text{``}30\text{''}\ (= 80)\) | |
| M1 | for a method to find the frequency (or area) between 20 g and 40 g, eg \(\text{``}50\text{''} + \text{``}80\text{''}\ (= 130)\) or \(\text{``}10\text{''} + \text{``}16\text{''}\ (= 26)\) | |
| A1 | for \(\dfrac{130}{400}\) oe |
Additional guidance
Evidence for this mark may be seen on the diagram
Accept equivalent methods
For M marks condone use of 2.5 for fd of 3 and/or 4.5 for fd of 5
Accept any equivalent fraction, decimal form, 0.32(5) or 0.33 or percentage form, 32.(5)% or 33%