Falling series whose differences are consecutive primes (-19, -17, -13, ...)

The same question, asked 2 times: 17 Sep 2024 S1*, 17 Sep 2024 S3. Every wording below, oldest first.

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Question 1
17 Sep 2024 S1
19 $Select the number from among the given options that can replace the question mark (?) in the following series. 96,77,60,47,36, ?$
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Question 2
17 Sep 2024 S3
21 $Select the number from among the given options that can replace the question mark (?) in the following series. 1225, 1184, 1147, 1116, 1087, ?$
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