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ivanzaharov [21]

3 years ago

7

the mean of marks scored by 100 students was found to be 40. Later on, it was discovered that a score of 53 was misread as 83. F

ind the correct mean.

1 answer:

liberstina [14]3 years ago

3 0

As the sum of marks of others remain unchanged , let their sum be x . As the mean using 83 was 40 , we have ,

(x +83)/100 = 40

x + 83 = 4000

x = 3917

Now mean using 53 ,

(x +53)/100

(3917+53)/100

39.7.

Hope it helps , plz mark as brainiest :-)

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Mumbi is approximately 845 kilometers away from Bangalore, and Mumbai is approximately 1160 km away from Delhi. The distances, m

Mazyrski [523]

Mumbi is approximately 845 kilometers away from Bangalore, and Mumbai is approximately 1160 km away from Delhi, then the ratio between these distances is

$\dfrac{845}{1160}=\dfrac{169}{232}.$

A. Bangalore to Mumbai: 116.5 cm;

Mumbai to Delhi: 174 cm

The ratio:

$\dfrac{116.5}{174}=\dfrac{233}{348}\neq \dfrac{169}{232}$

This option is false.

B. Bangalore to Mumbai: 42.25

Mumbai to Delhi: 58 cm

The ratio is

$\dfrac{42.25}{58}=\dfrac{845}{1160}=\dfrac{169}{232}$

This option is true.

C. Bangalore to Mumbai: 23.4 cm

Mumbai to Delhi: 29 cm

The ratio is

$\dfrac{23.4}{29}=\dfrac{117}{145}\neq \dfrac{169}{232}$

This option is false.

D. Bangalore to Mumbai: 16.9 cm

Mumbai to Delhi: 23.2 cm

The ratio is

$\dfrac{16.9}{23.2}=\dfrac{169}{232}$

This option is true.

E. Bangalore to Mumbai: 25.35 cm

Mumbai to Delhi: 34.8cm

The ratio is

$\dfrac{25.35}{34.8}=\dfrac{507}{696}=\dfrac{169}{232}$

This option is true.

Answer: correct options are B, D and E

8 0

3 years ago

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Darius is putting tiles on the roof of his house. After working for 3 1/3 hours, he has completed 4/5 of the roof. Can Darius pu

tangare [24]

Answer:

No.

Step-by-step explanation:

It is given that Darius is putting tiles on the roof of his house.

Darius had completed = $\frac{4}{5}$ th of the work

He takes time = $3 \frac{1}{3}$ hours to complete $\frac{4}{5}$ th of the work

The remaining work = $1 -\frac{4}{5}$

$=\frac{5-4}{5}$

$=\frac{1}{5}$

∴ Darius completes $\frac{4}{5}$ th of the work in = $\frac{10}{3}$ hours

So, $\frac{1}{5}$ th of the work in = $\frac{10}{3} \times \frac{5}{4} \times \frac{1}{5}$ hours

$=\frac{10}{12}$ hours

Therefore total time taken to complete the work $=\frac{10}{3}+\frac{10}{12}$ hours

$=\frac{40+10}{12}$ hours

$=\frac{50}{12}$ hours

$=4\frac{2}{12}$ hours

$=4\frac{1}{6}$ hours

Thus, Darius continues to work at the same rate will not be able to complete the work in 4 hours.

8 0

3 years ago

K + 12 ≥20, if k = 15 <br> HELP PLEASE!!

Andrei [34K]

Answer:

Step-by-step explanation:

k= 15

k+12 ≥ 20

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3 years ago

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Goryan [66]

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3 years ago

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Mrac [35]

Let x be the angle. The complement is 3x + 10. The sum of two complementary angles is 90. So,
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Plug x into the complement
3(20) + 10 = 70

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4 0

3 years ago