For JEE 2025 Aspirants...

Doubt to nahi hai par chemical kinetics ke PYQs revise kar raha tha and I realised....
Is question ke liye ye
t₉₉ = 10 ⨯ t₁/₂ = 3 ⨯ t₉₀
t₁/₂ = 120 de rakha tha to
t₉₉ = 1200 ho gaya so
t₉₀ = 1200 / 3 = 400
But pata chala ki jin jin logo ne 400 mark kiya tha sablo -1 mila... So formula laga ke kar lena bas... yahi kehna tha...