The missing number in the given figure is:
Statement: All flowers are beautiful. Some beautiful things are fragile. Conclusion I: Some flowers are fragile. Conclusion II: All beautiful things are flowers.
A particle is moving in a straight line. The variation of position $ x $ as a function of time $ t $ is given as: $ x = t^3 - 6t^2 + 20t + 15 $. The velocity of the body when its acceleration becomes zero is: