How does the formula consumption change once the baby starts solid?

My baby turned 7 months yesterday ,he used to drink formula 4 times a day, and took 1 night breast feed. Yesterday i started solids twice a day 1.5- 2 hours after formula feed.today my baby slept earlier than usual after the evening solid feed and i did not even realize he is sleeping for the night rather than a nap.he usually takes a formula feed after 3 hours of the evening solid right before sleeping .is this pattern normal?

How does the frequency /quantity of formula milk need to change once solids increase?