63,360, 63,366, 63,372, 63,378, 63,384, ... What is Barry's altitude above sea level, in inches, when he is standing on the 65th step above the one-mile step (counting the one-mile step itself as step #1)?

Respuesta :

You need to convert the sequence to a formula 

Since step 1 is 63,360 and each is 6 higher. 

First I will try... 

Altitude = 63,360 + 6x 

Lets check it with step 1 ... 

= 63,360 + 6(1) 
= 63,366 
wrong. 

6 too high 

So the formula would be 

Altitude = 6x + 63,354 

Lets test for known step 5 which the sequence says will be 63,384 ... 

= 6(5) + 63,354 
= 30 + 63,354 
= 63,384 

Looks good ! 

Now... 

For step 55 just plug in 55 as X to solve. 

= 6(55) + 63,354 

then simplify
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