Study the given bar graph and answer the question given follows:
The below bar graph shows the time taken by a boy alone and a girl alone to complete the respective projects. (in days)
Find the total time taken by one boy and one girl together working on project Q and project S.
Answer & explanation
Correct answer: option 2
Project Q
Time taken by boy = 15 days
Time taken by girl = 20 days
Let the total work on Project Q = LCM of 15 and 20 i.e. = 60
Time taken by them to complete the work on Project Q = \(\frac{60}{7}\) days
Project S
Let the total work on Project S = LCM of 20 and 30 i.e. = 60
Time taken by them to complete the work on Project S = \(\frac{60}{5}\) = 12 days
Total time = \(\frac{60}{7}\) + 12 = \(\frac{60+84}{7}\) = \(\frac{144}{7}\) days