Team A can built a project in 4 hours less than the time taken by Team B to built the same project. The ratio of the strength of Team A to that of Team B is ______. If it is given that the efficiencies of each member of both the teams is same (where the efficiency is measured in work done per hour), then which of the following ratios will satisfy the condition? (i) 5:3   (ii) 25:38   (iii) 15:11   (iv) 20:25

Since Team A is taking less time than Team B and each member has the same efficiency. With this we can say that the strength of Team A will be greater than that of Team B. Thus only (i) and (iii) satisfy the condition (first term is greater than that of second term). Alternative Method:                             Team A     Team B Time:                        T             T+4 Strength:                   A               B Work Done:             AT     =     B(T+4) ؞ Then,  AT = B(T+4) A/B = (T+4)/T Thus, we can say that A > B. Hence only option (i) and (iii) satisfy the condition.