Mr. Velez is a single parent with an infant and a 4-year-old. Mr. Velez works 40 hours a week while his children are in a childcare center full-time. Take a look at the average cost of care in Connecticut.

In my response, the cost of care will include child care, groceries/necessities, and housing expenses. Connecticut is currently ranked as having the sixth highest child care costs in the nation. In Connecticut, Mr. Velez can expect to pay an average of $14,000 per year for daycare costs. Private nannies and other child care options will be more expensive at around $30,000 per year. The costs of transporting the children to and from child care can vary depending on whether Mr. Velez utilizes public transportation or commutes. Mr. Velez can also expect to spend approximately $1,800 for groceries and other necessities each month. Depending on whether Mr. Velez rents or finances his home, the expense can vary. He will pay an estimated $1,600 - $2,000 in rent each month. A mortgage will be slightly less expensive.

I'm going to assume this question is in reference to the cost of childcare. In Connecticut, full-time childcare is, to put it simply, very expensive. A 2016 report I'll link below declares the average cost can be as much or more than in-state college tuition, presumably before factoring in multiple children and infant care, as Mr. Velez would require. The Washington D.C. based think tank New America collaborated with multiple sources including government-collected data and childcare sites, such as Care.com, to create a site they call the "Care Index." They state their project "examines cost, quality, and availability data in all fifty states . . . no single state does well in all three categories." The cost for in-home care runs around thirty thousand dollars, childcare centers run a little less than half of that amount at eleven thousand, which averages to $19,000 per year. However, for the presumably working-class Mr. Velez, there is help. The Connecticut Early Childhood Alliance offers what they call Care4Kids, which recognizes the huge burden full-time childcare places on low- to mid-class families. It is a Congress-approved childcare subsidy program, and although it has been hit with drawbacks and closures, it recently received an expected $14 million in funding. So although childcare expenses can reach nearly thirty percent of the median household income in Connecticut, with the Care4Kids program it's possible Mr. Velez could receive assistance in paying for childcare as a full- time working single parent.
This is a general overview of your question, but I'd recommend, depending on how in-depth your answer needs to be, researching specific care centers that might tell you the particular costs for two children or for infant care.
http://www.earlychildhoodalliance.com/care4kids2

https://ctmirror.org/2016/09/30/average-child-care-in-ct-costs-as-much-as-in-state-college-tuition/