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Question
Which term of an A.P. 16, 11, 6, 1, ... is – 54?
Solution
A.P. = 16, 11, 6, 1, ...
It is given that
tn = – 54
a = 16, d = t2 – t1 = 11 – 16 = – 5
∴ tn = a + (n – 1)d
– 54 = 16 + (n – 1)(– 5)
– 54 = 16 – 5n + 5
21 – 5n = – 54
– 5n = – 54 – 21
– 5n = – 75
n = `75/5` = 15
∴ 15th term is – 54.
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| Treasure Hunt is an exciting and adventurous game where participants follow a series of clues/numbers/maps to discover hidden treasure. Players engage in a thrilling quest, solving puzzles and riddles to unveil the location of the coveted prize. While playing a treasure hunt game, some clues (numbers) are hidden in various spots collectively forming an A.P. If the number on the nth spot is 20 + 4n, then answer the following questions to help the players in spotting the clues: |
- Which number is on first spot? 1
- Which spot is numbered as 112? 2
OR - What is the sum of all the numbers on the first 10 spots? 2
- Which spot is numbered as 112? 2
- Which number is on the (n – 2)th spot? 1
