Which of the following has more inertia:
(a) a rubber ball and a stone of the same size?
(b) a bicycle and a train?
(c) a five rupees coin and a onerupee coin?
Answer
Inertia depends on mass of the body.
More the mass, more the inertia
Let’s look at all these parts

a rubber ball and a stone of the same size
A stone will have more mass than a rubber ball of the same size.
Since more mass means more inertia,
the inertia of the stone will be more than the rubber ball.

a bicycle and a train
A train will have more mass than a bicycle.
Since more mass means more inertia,
the inertia of the train will be more than the bicycle.

five rupees coin and a onerupee coin
A fiverupees coin will have more mass than a onerupee coin.
Since more mass means more inertia,
the inertia of the fiverupees coin will be more than the onerupee coin.