Cheap and Best, a Kirana shop bought some apples at 4 per rupee and an equal number at 5 per rupee. He, then sold the entire quantity at 9 for 2 rupees. What is his percentage profit or loss?

LCM(4,5) = 20
So, 20 apples each were bought at 4/Re and 5/Re.
So, he spent Rs 5 and Rs 4 i.e. a total of Rs 9 for 20+20 = 40 apples.
So, CP (1 apple) = 900/40 = 22.5 paise
So, CP (9 apples) = 9*22.5 = 202.5 paise
SP (9 apples) = 200 paise
So, Loss % =(202.5-200)/202.5
= 0.012345679
= 1.23%