Time Weight Problem because, problems, additional, holding, helping

Nishant1

I'm having a little problem understanding one of the problems int he CFAI text if someone dont mind helping me, P 250, Example 5.

On Jan 1 03, W fund had market value of $100k
Jan 1 to April 30, $10k in cap gain
May 1, $2k dividend paid, all were reinvested
May 1, additional $20k reinvested. Total value $132 (100+10+2+20)

Shouldn't the first holding period be from Jan 1 to April 30 because:
1. Thats the first 3 months, quarterly
2. Ending value given at April 30, $10k in cap gain

So HP1 = 10/100 = 10%

But the example has it as 12/100 = 12%?????