Kya Main Fails Hoon? Still Confused About Consideration!!!

Main 3 din mein exam hai aur mujhe abhi bhi ek cheez clear nahi hai. Kya aap logon ne kaha hi hoga, koi bhi consideration deta hai phir bhi contract na ban sakta hai. Lekin phir aapke paas uska example kaha hai? Main khud se socha hoon, kai baar baat ki hai. Aapke paas koi aisa example hai jo yeh dekhaye ki consideration dene wala contract ka banaya nahi ja sakta hai. Main yeh pehli baar soch raha hoon, kya main hi idhar se galat hu? Abhi ek baar phir bhi sochunga kya.