Q.Halsey premium plan is based on

The Halsey premium plan pays a bonus on time saved, so it is based on time — option (b).

In +2 Class-12 Cost Accounting (CHSE Odisha, NCERT/CBSE-aligned), under the Halsey plan:

• The worker gets guaranteed time wages for the actual time taken.
• Plus a bonus of 50% of the time saved (standard time − actual time) at the hourly rate. …

Total earnings under Halsey = normal (time) wages + bonus on time saved — option (c).

In this CHSE Odisha +2 Cost Accounting topic, the Halsey plan guarantees the worker his normal time wages (actual time × rate) and adds a bonus equal to 50% of the wages of the time saved:

…

Halsey premium plan is based on time (time saved) — option (b).

Under the Halsey plan a worker gets guaranteed time wages plus a bonus equal to 50% of the time saved valued at the hourly rate:

• Time saved = Standard time - Actual time
• Bonus = 50% x Time saved x Rate per hour …