how to answer the following question:

what are the effects of increase in both demand and supply at equal propotion? explain withe help of diagram.

Dear student
This is a case of simultaneous increase in demand and supply.
When increase in demand is exactly equal to increase in supply there will be no change in the equilibrium price but quantity will increase.

Here equilibrium quantity increase from OQ to OQ' .
This is because both demand and supply happen to rise.

Regards