On a final exam, 75 percent of a class had scores that were greater than 70, and 60 percent of the class had scores that were less than 85. what percent of the class had scores that were greater than 70 but less than 85 ?

The answer is 35.

35% of the class had scores that were greater than 70 but less than 85.

Step-by-step explanation:

Let's assume the number of students in the class =100

If 75% of the class scored greater than 70, then, it means 25% (100-75) of the scores were less than or equal to 70

In other words, 25 scores were less than or equal to 70.

If 60% of the class had scores that were less than 85, then, it means 40%(100-60) of the scores were greater than or equal to 85

Therefore, of the 100 scores, 25 scores were LESS THAN OR EQUAL to 70, and 40 scores were GREATER THAN OR EQUAL to 85.

We've now accounted for 65 (25+40) scores, which means the remaining 35 (100-65) scores must be between 70 and 85.

after simplifying it i got: -36.25 as my answer. hope that !

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 ☺