Work backwards.

She had 30 muffins after giving 1/3 to her sister.

2/3 = 30

3/3 = 30 × 3/2 = 45

Add the 5 she gave her friend → 45 + 5 = 50

She had 50 muffins at first.

Thanks. Your explanation is much better than my child’s teacher.

Haha…perhaps I should become a Math tutor? 🙂

I thought u r a teacher

Wah…paiseh. I’m not good enough to be a teacher lah. 

Just a regular daddy with schooling kids.

U r too humble BigDevil….u r better than my child school teacher

total muffins ——- 5 + 1u + 1u + 1u = 3u + 5
2u ——- 30
1u ——- 30/2 = 15
3u + 5 ——- 3 x 15 + 5 = 50

Ans : 50 muffins.