Life insurance addl amount

Can someone explain how the section about “the family’s living expenses declining by $30k per year” is pertinent to this question? At first glance, this seems like something to include in the calculation but it is not included in the answer

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In the question it says family expenses = 95,000
Then we have 2 calculations in answer
Oliva’s expenses = 50,000 , Children 15,000 Add together 65,000
95,000 - 65,000 = 30,000
The expenses drop by 30,000 but we need to take into account different length of payment streams for Olivia and children.