Exercise 1: Estimating O(2^n) Running Time at n=40 — Possible Solution
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GIVEN
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1 billion (1e9) operations per second, n = 40

STEP 1: TOTAL OPERATIONS
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2^40 = 1,099,511,627,776 (~1.10 x 10^12 operations)

STEP 2: CONVERTING TO TIME
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seconds = 1.10 x 10^12 / 1 x 10^9 = 1,099.5 seconds

STEP 3: CONVERTING TO A HUMAN-READABLE UNIT
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1,099.5 seconds / 60 = 18.33 minutes

RESULT
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An O(2^n) algorithm at n=40 would take approximately 18.3 minutes at
1 billion operations per second.

WHY THIS WORKS AS AN ANSWER
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The total operation count is computed directly from the definition of
2^n, converted to seconds using this chapter's own 1-billion-ops-per-
second assumption, and then converted again into a genuinely readable
unit (minutes) rather than left as an unwieldy raw number of seconds.