A report card has six marks. The average of the first and second marks is 72%. The average of

the second and third marks is 75%. The average of the third and fourth marks is 77%. The

average of the fourth and fifth marks is 78%. The average of the fifth and sixth marks is 79%.

a) Determine the overall average. b) Determine the average of the first and sixth marks.

a) Overall average = 76%

b) Average of first and sixth marks = 75%

Step-by-step explanation:

Let's call the marks a, b, c, d, e and f, in this order.

Then, we can write the following equations:

(a+b)/2 = 0.72 -> a + b = 1.44 (eq1)

(b+c)/2 = 0.75 -> b + c = 1.5 (eq2)

(c+d)/2 = 0.77 -> c + d = 1.54 (eq3)

(d+e)/2 = 0.78 -> d + e = 1.56 (eq4)

(e+f)/2 = 0.79 -> e+ f = 1.58 (eq5)

If we sum all equations, we have:

a + 2b + 2c + 2d + 2e = f = 7.62 (eq6)

Then, we make (eq6) - (eq2) - (eq4):

a + b + c + d + e + f = 4.56 (eq7)

a) The find the overall average, we just need to divide (eq7) by 6:

Overall average = (a + b + c + d + e + f)/6 = 0.76 = 76%

b) First we need to make (eq7) - (eq2) - (eq4):

a + f = 1.5

Then, the average is:

Average = (a+f)/2 = 0.75 = 75%

1. x> -5

2. x< 8

step-by-step explanation:

1. 2x> -10

divide by 2 from both sides of equation.

2x/2> -10/2

simplify, to find the answer.

-10/2=-5

x> -5 is the correct answer.

2. 3x< 24

divide by 3 from both sides of equation.

3x/3< 24/3

simplify, to find the answer.

24/3=8

x< 8 is the correct answer.

i hope this you, and have a wonderful day!

answer: 16

step-by-step explanation: first you would add 6+6 which equals 12 then add 2+2 which equals 4. then add 12 + 4 which is 16.

hope this ^_^