Question

the ratio of adults to children is 7:3. based on this ration, if there was 370 people how many where children

Answer 1

In a ratio of 7:3, for every 7 adults you have 3 children.  So 30% of the total are children.  I.e.  if you have 10 people  .7 times (10) are adults or 7 and .3 times (10) are children or 3.    So for 370 people,  .3 times 370 are children, or 111.