Answer:Here are the answers to the problems: 1. C. 156 - This is an arithmetic sequence with a common difference of 1. To find the total number of seats, we need to find the sum of the first 8 terms. The formula for the sum of an arithmetic sequence is Sn = (n/2)(a1 + an), where Sn is the sum of the first n terms, a1 is the first term, and an is the nth term.- In this case, n = 8, a1 = 15, and a8 = 15 + (8-1)1 = 22.- Therefore, S8 = (8/2)(15 + 22) = 156.2. D. 545 - This is an arithmetic sequence with a common difference of 5. To find the total number of passengers, we need to find the sum of the first 7 terms.- Using the same formula as above, n = 7, a1 = 40, and a7 = 40 + (7-1)5 = 60.- Therefore, S7 = (7/2)(40 + 60) = 545.3. C. 630 - This is an arithmetic sequence with a common difference of 50. To find the total distance traveled after 10 hours, we need to find the sum of the first 10 terms.- Using the same formula, n = 10, a1 = 40, and a10 = 40 + (10-1)50 = 490.- Therefore, S10 = (10/2)(40 + 490) = 630.4. B. 78 - This is an arithmetic sequence with a common difference of -1. To find the total number of boxes, we need to find the sum of the first 12 terms.- Using the same formula, n = 12, a1 = 12, and a12 = 12 + (12-1)(-1) = 1.- Therefore, S12 = (12/2)(12 + 1) = 78.5. A. 460m - This is an arithmetic sequence with a common difference of 70. To find the total distance traveled after 5 minutes, we need to find the sum of the first 5 terms.- Using the same formula, n = 5, a1 = 180, and a5 = 180 + (5-1)70 = 460.- Therefore, S5 = (5/2)(180 + 460) = 460.6. D. 640 - This is a geometric sequence with a common ratio of 2. To find the total earnings for the week, we need to find the sum of the first 7 terms.- The formula for the sum of a geometric sequence is Sn = a1(1-r^n)/(1-r), where Sn is the sum of the first n terms, a1 is the first term, and r is the common ratio.- In this case, n = 7, a1 = 10, and r = 2.- Therefore, S7 = 10(1-2^7)/(1-2) = 640.7. C. S= a1/(1-r) - This is the formula for the sum of an infinite geometric sequence, where a1 is the first term and r is the common ratio. This formula only works if the absolute value of the common ratio is less than 1 (|r| < 1).8. D. Infinite Geometric Series - A geometric series is the sum of the terms in a geometric sequence. When the common ratio is -1, the terms alternate between positive and negative values, resulting in an infinite geometric series.9. A. 90 in - This is an example of a geometric sequence with a common ratio of 0.8. To find the total distance the pendulum travels until it stops, we need to find the sum of an infinite geometric sequence.- Using the formula from question 7, a1 = 18 and r = 0.8.- Therefore, S = 18/(1-0.8) = 90.10. B. 13.33 m - This is an example of an infinite geometric sequence with a common ratio of 0.3. To find the total distance the ball travels, we need to consider both the upward and downward distances.- The upward distances form a geometric sequence: 4, 1.2, 0.36, ...- The downward distances form the same geometric sequence, except for the initial 4 meters.- Therefore, the total distance is: 4 + 2 * (4/(1-0.3)) = 13.33 meters.