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3 years ago

O put on Your Thinking Cap!

Mathematics

1 answer:

True [87]3 years ago

7 0

Answer:

Michelle must get an 80 on her next test to keep her average score.

Step-by-step explanation:

Since Michelle got an average score of 80 on two tests, to determine what score she must get on the third test so that her average score for the three tests is the same as the average score for the first two tests, the following calculation must be performed:

X / 2 = 80

X = 80 x 2

X = 160

X x 3 = 80 x 3

X x 3 = 240

X = 240/3

x = 80

So, Michelle must get an 80 on her next test to keep her average score.

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A university offers 3 calculus classes: Math 2A, 2B, and 2C. A set of students have each taken at least one of the three classes

lyudmila [28]

Answer:

157

Step-by-step explanation:

We are given that

Number of students in maths 2A=n(2A)=51

Number of students in math 2B=n(2B)=80

Number of students in math 2C=n(2C)=70

Number of students in maths 2A and 2B= $n(A\cap B)=15$

Number of students in maths 2B and 2C= $n(B\cap C)=13$

Number of students in maths 2A and 2C= $n(A\cap C)=20$

Number of students in maths 2A ,2B and 2C=4

We have to find the number of students in a set.

Formula: $n(A\cup B\cup C)=n(A)+n(B)+n(C)-n(A\cap B)-n(B\cap C)-n(A\cap C)+n(A\cap B\cap C)$

Substitute the values in the given formula

$n(2A\cup 2B\cup 2C)=51+80+70-15-13-20+4=157$

Hence, total number of students in a set=157

4 0

2 years ago

Tia shares 53 balloons equally among 4 children. How many balloons will be left over?

lilavasa [31]

Answer:

Step-by-step explanation:

13 x 4 = 52

53 - 52 = 1

8 0

3 years ago

Read 2 more answers

Mary is five times as old as Fred. In three years Mary will be 4 times as old as Fred. Find their present ages?

igomit [66]

ans

here let mary age be x and fred be y

1st equation

x= 5y

2nd equation

x+3 =4(y+3)

now from 1st equation putting value of x in equation 2

x+3 = 4y+12

5y+3 = 4y +12

y = 9

so fred is 9 and mary is 45

5 0

3 years ago

As a _____, allison buy jeans; and as a _____, allison make t-shirts. so, she plays both roles.

Svetlanka [38]

As a customer allison buy jeans; and as a tailor allison makes t shirts. so she plays both roles

6 0

3 years ago

Read 2 more answers

In right trapezoid MNPQ

Gala2k [10]

Answer:

about 252.78 ft

Step-by-step explanation:

Define angle QMP as α. Then ...

MN = 60·sin(α)

NP = 60·cos(α)

area MPN = (1/2)(MN)(NP) = 1800sin(α)cos(α)

PQ = 60tan(α)

area MPQ = (1/2)(MP)(PQ) = 1800tan(α)

The ratio of areas is 2.5, so we have ...

1800tan(α) = 2.5·1800sin(α)cos(α)

1 = 2.5cos(α)² . . . . . . divide by 1800tan(α)

cos(α) = √0.4 . . . . . . solve for cos(α)

Then the perimeter is ...

Perimeter = MN +NP +PQ +QM = 60sin(α) +60cos(α) +60tan(α) +60/cos(α)

= 60(sin(α) +cos(α) +tan(α) +sec(α))

= 60(0.774597 +0.632456 +1.224745 +1.581139)

= 60(4.212936) = 252.776

The perimeter of the trapezoid is about 252.776 feet.

_____

With perhaps a little more trouble, you can find the exact value to be ...

perimeter = (6√10)(7+√6+√15)

3 0

3 years ago