Question

In Physics, the average of marks scored by Dev and Krish is 45.5 while that by Dev and Shiva is 46.5. If the average of marks scored by Dev, Krish and Shiva is 47,
find the average of marks scored by Krish and Shiva.​

Answer 1

Answer:

48.5

Step-by-step explanation:

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Answer 2

The average marks scored by Krish and Shiva is 49 marks.

Step-by-step explanation:

Let the no. of marks obtained by  Dev, Krish and Shiva be x,y,z respectively.

According to the question , it is given that,

(x+y)/2=45.5-----------(1)

(x+z)/2=46.5------------(2)

(x+y+z)/3=47------------(3)

We need to find (y+z)/2=?

For this let us solve eq. 1,2 and 3, we get

(x+y)=91--------------(4)

(x+z)=93--------------(5)

(x+y+z)=141-----------(6)

Now, on calculating (6)-(5), we get,

z=141 - 91=50

⇒z=50-------------(7)

Similarly, on calculating (6)-(4), we get,

y = 141 - 93 = 48

⇒y=48-------------(8)

Lastly, on calculating (y+z)/2

⇒(y+z)/2 = (48+50)/2   (from equations 7 and 8)

⇒(y+z)/2=98/2

⇒(y+z)/2=49

Hence the average marks of Krish and Shiva is equals to 49 marks.