Question

Why the single bond is more stronger than the double bond.

Answer 1

Actually the statement should be Why the Double bonds are stronger than single bonds?
The reason is that in the double bond the atoms share 4 electrons while in the single bond only 2 electrons are shared.
Because of this, in double bonds the atoms are closer to each other and you will have apply more energy to take them appart and hence they are stronger than the single bonds, in which the atoms are relatively away from each other.