Higher June 2019 Paper 1 Q16
16 There are three dials on a combination lock.
Each dial can be set to one of the numbers 1, 2, 3, 4, 5
The three digit number 553 is one way the dials can be set, as shown in the diagram.
(a) Work out the number of different three digit numbers that can be set for the combination lock. (2)
(b) How many of the possible three digit numbers have three different digits? (2)
| Answer | Mark | Mark scheme |
|---|---|---|
| 125 | M1 | for method to find the number of 3 digit combinations, eg \(5^3\) or \(5^3 - 1\) |
| A1 | for 125 or 124 |
| Answer | Mark | Mark scheme |
|---|---|---|
| 60 | M1 | for method to find the number of combinations with 3 different digits eg \(5 \times 4 \times 3\) or finds there are 65 combinations that do not have 3 different digits |
| A1 | cao |