Question

para alumbrar un parque, se colocan luminarias a lo largo de una longitud de 100 metros, si la primera se coloca en el metro 1, la siguiente en el metro 4, la que sigue en el metro 7, y así sucecibamente. en las siguientes posiciones se colocará una luminaria exepto en el metro: a)13 b)19 c) 21 d)28 ayudaaaaaaa​

Answer 1

Answer:

c)21

Step-by-step explanation:

"To light a park, luminaries are placed along a length of 100 meters, if the first is placed in meter 1, the next in meter 4, the next in meter 7, and so on. in the following positions a luminary will be placed except in the subway:

a)13 b)19 c) 21 d)28? "

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Luminaries position:

• 1, 4, 7, ...

It makes an AP with the first term of 1 and common difference of 3

The formula for this AP is:

• aₙ = 1 + 3(n-1) = 1 + 3n - 3 = 3n - 2

From the given options, only one is not in the same format:

• c) 21

because

• 21 = 3n - 2 ⇒ 3n = 23 and n= 23/3 is not an integer

Answer is: c) 13