Bah, no time debate over things like this.
The preference of correction:
1)Canceling
- Save time
- Take ups space
2)Liquid Paper
- Take time to dry (might forget to rewrite the liquided part)
- Gel ink will smear.
3) Correction tape
- Lousy brand tape may end up the tape sticking to the next page
- Gel ink might smear depending on brand.
- Save time
4) Stickers
- Save time
- Neat
- Cannot stack too many times
Depending on what to use, use your brain. Thank you.
@vick
The method I do is kinda clumsy, my tuition teacher told me a better method, but I've forgotten.
1st step
24 = 4/2 (2a - 3d)
12 = 2a + 3d
a = 6 - 3/2(d)
2nd step
55 = T
1 + T
3 + T
5 + T
7 + T
955 = a + a + 2d + a + 4d ...... (lazy type

, the 1st line should have explained)
55 = 5a +20d
a = 11 - 4d
3rd step (solve simultaneously)
11-4d = 6 - 3/2(d)
22-8d = 12 - 3d
10 = 5d
d = 2
a = 3