Question

In a club, the ratio of the number of adults to the number of children is 12 :7. The ratio of the number of boys to the number of girls is 3 : 2. If there are 42 girls, how many members are there altogether?

Answer 1

given no. of adult to the no.children:-12/7
boys to girls:-3/2
no.of girls:-42
3/2+12/7=45/14 to the no .girls 
45/14x42
=135 (ans)
so, no of members =135

Answer 2

In a club, the ratio of the number of adults to the number of children is 12 :7. The ratio of the number of boys to the number of girls is 3 : 2. If there are 42 girls, how many members are there altogether?
solution :------
               Let the Number of adults = 12x
                 and the number of children = 7x
             According to question ,
                                     Number of boys / number of girls = 3/2
                                     Number of boys  =  3/2 * number of girls.
           Given , Number of girls = 42
         Therefore Number of boys  = 3/2 * 42
                                               = 3*21
                                               = 63
   Therefore Number of Boys = 63

   Both Boys and girls are children , therefore number of Children = number of boys + number of gilrs
                                                 = 63 + 42
                                                 = 105
Number of children = 105
   therefore , 7x = 105
               => x = 105/7
               => x = 15

Hence Number of Adults = 12 x
                                   =  12 * 15
                                   = 180

Therefore , total members = adults + children
                                       = 180 + 105
                                        = 285

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