1.

100 people go to a party there are 100 plates of food each male eats in 4 plates, each female eats in 3 plates and 4 children eat in one plate and all the plates are used. what is the total no of each male female and chlidren?

Answer»

It can be done only by hit and trial METHOD as there are only two equation and 3 unknown .
But if you are applying some logic in it then you will get the solution  very fast as many case will ELIMINATE . 
Solution is : No. of children = 76 , No of Women = 15 and No. of men = 9 

First find the number of children . It can only be MULTIPLE of 4 and can only be 76 as if its less than 76 say 72 then if all other are women then number of plate will be 72/4 + 28*3 = 18+84 = 102 which is greater than 100 . Similarly you can discard all the other No. of children less than 76. 
If you are taking No. of children = 76 then total plate used will be 19 and left plates are 81 .
Also number of person remaining is 24(100-76=24)
Let x number of person be women , then no. of men = (24-x)
x*3 + (24-x)*4=81
or, x = 15
No . of children = 76
No. of Women = 15
No of Men = 100- (76+15) = 100-091 = 9 


Hope this WOULD have cleared your doubt .


Discussion

No Comment Found

Related InterviewSolutions