Question

the average height of 5 people 15ft . A new friends join them and the average increases by 1 ft . what is height of new friend​

Answer 1

Answer:

21ft

Explanation:

5×15ft = 75ft

6×16ft = 96ft

96ft - 75ft = 21ft

Answer 2

The height of new friend is 21 ft.

Step-by-Step Solution:

Given:

• The average height of 5 people = 15 ft
• New average after new friend joins = 15+1=16 ft

To be found: The height of new friend.

Formula Used: $Average=\frac{\text TotalSum of item}{Total No. of items}$

Solution:

Let the 5 friends be a,b,c,d,e respectively, and let the new friend be f.

Since we know that average height of 5 people is 15 ft, which means,

$\frac{a+b+c+d+e}5=15\\a+b+c+d+e=15\times 5\\a+b+c+d+e=75....(i)$

Now if the new friend joins them, then the average increases by 1 ft.

Therefore, the average of 6 people will be 15+1 = 16ft.

So, Now the equation will be,

$\frac{a+b+c+d+e+f}{6}=16\\a+b+c+d+e+f=16\times 6\\a+b+c+d+e+f=96$

Now, using equation (i)

$\because a+b+c+d+e=75$

Putting this value in the equation,

$75+f=96\\f=96-75\\\therefore f=21$

Therefore, the height of new friend is 21 ft.

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