Plz ! , boris is playing on the mall escalators. one escalator goes up, one goes down, and one is out of service; otherwise, they're all identical. the up and down escalators go at the same speed. you can assume that boris always runs at the same speed. boris can run up the up escalator in 6 seconds. he can run up the down escalator in 30 seconds. how long does it take him to run up the out-of-service escalator? explain your answer

10 sec

Step-by-step explanation:

Given

Boris can run up the escalator in 6 sec

Also he can run up the down escalator in 30 sec

i.e. He travel same distance either ways

Let the distance be x and v be the speed of boris and be the speed of escalator.

----1

----2

Equating 1 and 2

substituting in 1

Thus form above equation we can say that it requires 10 sec for Boris to climb up in out of service escalator.

step-by-step explanation: so we look at the formula un = a + (n-1)d

un is the amount of seats

n is the nth term aka row number

a is the original sequence/row number

d is the difference between each term

so in this a=22 d=6 and n can remain as n because we are simply formjng a rule

lets put these in the equation

un=22+(n-1)(6)

this is your answer to part a

however

lets double check that this is correct, we'll try putting it into the second term

un=a+(n-1)d

u2=22+(2-1)(6)

u2=22+6

u2=28

as the question said the second row has 28 seats so now we know the formula we made is correct.

as for part b

un=a+(n-1)

its asking us to find a row with 100 seats.

remember un was the amount of seata so all we do is substitute this in.

un=100 a=22 d=6

un=a+(n-1)d

100=22+(n-1)(6)

so now we simplify to find n which is the row number.

100-22=22+(n-1)(6)-22

78=(n-1)(6)

78/6=(n-1)(6)/6

13=n-1

13+1=n-1+1

14=n

so now we know that in the 14th row there is 100 seats.

hope this and that you understood! its my first time using the app or anyone out on here : p its also me to revise so a bunch! ask more questions if you dont understand ☺

answer

a) the midrange of the data set shown is 85.5

step by step explanation

let's find the midrange.

the midrange is nothing but add the greatest value and the least value, then divide it by 2.

here the greatest value = 99

the least value = 72

midrange = (99 + 72)/2

= 171/2

midrange = 85.5

you.