This should be the answer:

1. The number of candidates was constant for the first 10 days, so the number of candidates after 10 days is still 740.
2. The number of candidates doubled every day for the last 5 days, so:
    - Day 11: 740 x 2 = 1480
    - Day 12: 1480 x 2 = 2960
    - Day 13: 2960 x 2 = 5920
    - Day 14: 5920 x 2 = 11840
    - Day 15: 11840 x 2 = 23680
3. Therefore, the number of candidates after the registration is 23680.

So, the final answer is 23680.

During the 2010 Post-Jamb registration exercise which lasted 15 days the number of candidates registering doubled every day in the last five days but was constant in the first 10 days. If the number of candidates at the beginning was 740, what was the number after the registration?

Earlier discussion