Given the total number of girls = 42
The ratio of the number of boys to the number of girls is 3: 2, which means that the children are divided into five parts out of which 2 parts are girls
Given the total number of girls = 42
Therefore 2 parts of children= 42
So 1 part of children = 21
Total number of children = 5 x 21 = 105
Given the ratio of the number of adults to the number of children is 12:7 which means that out of 19 parts 7 parts are children.
7 part of all = 105. Therefore 1 part of all = 105/7 = 15
So 19 part = 19x15=300-15=285