Chapter 6 Example 7 Query about normal basis allowance

In the question, Adam purchased a car (105g/km) on 1 October 2019. The car is used for 60% business.

When I look at the answer, the fact that the car has been bought for only half the year (Oct, Nov, Dec, Jan, Feb,Mar) has not been taken into consideration for calculation of Capital Allowances.. I feel the calculation should be multiplied by the 6/12. Does this not apply in a situation when a car is used both for business and privately?

Thank you