Question

Conduct the survey of 20 households in your locality to know the sex ratio.collect the information in given proforma age group 0-,15-59,60+

Answer 1

Just randomly prepare a list of members of each household. Name them as you wish. Do this for 20 households. Then, count the total number of female and male according to your report.
After that, divide the no. of female by the no. of male.
Suppose let the no. of male and female be x and y
Therefore, ratio will be y/x
Convert it to the simplest fraction, and you will get your ratio say a:b