manufacturing a/c

Hallo,

I have an example with Statement of comprehensive income, to build it out of a trial balance.
The example includes as well a manufacturing account, when solving it, I notice the following in the solution:

Manufacturing a/c.
.
.
Production Overhead
Depreciaion at cost
Premises ((5% 800) 80%) = 32
Plant ((20% 250) 70%) =35
Motor vehicle ((20% 100) 20%) = 4
Loss on disposal of vehicle (1 20%) = 0.2

My Q is about Motor vehicles:
The example says that the deprection on motor vehicles is 20% and out of this amount another 20% is apportioned to production, i.e. this goes to the manufacturing a/c.

So, motor vehicle cost is 124.
Then, there is a disposal of a motor vehicle with cost 24, depr. 14, NBV 10, sold for 13, loss 1 = cost of motor vehicle in manuf. a/c is 124 – 24 = 100

If we look at the loss on disposal of motor vehicle above of 0.2, when depreciation is 14, why depreciation is applied on the loss of 1, and not either use 20% on cost of 24, or directly the depr. of 14, in the manufacturing a/c? I don’t understand.

Thank you!