The cost of n dozen banana is x rupee more than 100 rupee and the cost of 6n dozen banana is 14x rup

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15 Sep 2011 banana

The cost of n dozen banana is x rupee more than 100 rupee and the cost of 6n dozen banana is 14x rupee less than 700 rupee. Which of the following is the cost of 1 dozen banana (Given that n and x are positive integers)

OPtion

1) 25
2) 30
3) 35
4) 40
5) 45
6) 50
7) 55
8) 60
9) 65
10) none of these

Solution

let the cost of 1 dozen banana is y rupee
then n*y = 100+x
and 6n*y = 700-14x
take n*y = 100+x from first equation in the second equation, we will get
6(100+x) = 700-14x
or 600+6x = 700-14x
or 20x = 100
or x = 5
on putting x=5, n*y = 100+5 = 105

Correct Option: 3 Best Solution (5)

marudhupandian .p   13 years AGO

n=x+100,then 6n=700-14x solving these two eqns we get n=105 x=5.here 1 dozen=35, 35+35+35=105 ie 3dozens=105,18dozens=630 where other options are not satisfy this condition

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jai Narayan Mishra   13 years AGO

BY hit and trial it is clear that 35 is right one

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harikrishnan   13 years AGO

cost of n dozen is 100+x socost of 6n dozn is600+6x
given is 6n dozen cost is 700-14x by solving these two can get x=5
so cost of 6n dozen = 700-14*5= 630
and cost of n dozen = 100+5 = 105
since the n and x are integers 105 and 630 are should be divisible by the cost so 35 isthe answer

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susmit   13 years AGO

(100+x)/n = (700-14x)/6n
so x=5 .
so cost of 1 dozen banana is 105/n and since n is
an integer answer is 35 ( 105 is not dicvisible by any other answer)

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vignesh   13 years AGO

x+100=700-14x
x=5
ndozen=105
6n dozen=630
i dozen=35

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