In a boat there are 8 men whose average weight is increased by 1 kg when 1 man of 60 kg is replaced by a new man. What is weight of new comer?
A. 70 kg
B. 66 kg
C. 68 kg
D. 69 kg
Answer: Option C
Solution(By Examveda Team)
Member in group × age increased = difference of replacementOr, 8 × 1 = new comer - man going out
Or, new comer = 8 + 60
Or, new comer = 68 kg.
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Comments ( 4 )
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8(x+1)-N=8x-60
N=68
I think the unit should be in kg not year as given.
Suppose, the average weight of 8 men before replacement is x, Hence total weight of 8 men would be 8x. Now, let's say the weight of the new man is y. Hence, replacement can be represented with following equation
8x + y - 60 ………(1)
Now, due to replacement, average weight of boat has increases by 1 I.e. x + 1
So, New total weight of the 8 men can be represented by following equation
8(x+1) …………(2)
But equation (1) & (2) are equal, as both of them represents new total weight on boat.
Hence,
8x + y - 60 = 8(x + 1)
8x + y - 60 = 8x + 8
y - 60 = 8
y = 68 kg.
So the weight of the newly added man is 68 kg.
new comer = weight of separated member+(increase in average + members in group)
new comer=60+(1*8)
=68