In a “keep-fit” gymnasium class, there are fifteen females enrolled in a weight-loss program. They all have been grouped in any one of the five weight-groups W1, W2,W3,W4 or W5. One instructor is assigned to one weight-group Rulpali and Renuka are also in one weight-group . Rupa, Radha, Renuka, Ruchika , and Ritu belong to different wight -groups. Somya cannot be with Ritu, and tara cannot be with radha. Komal cannot be with Radha ,Somya , or Ritu . Shahira is in W1 and Somya is in W4 with Ruchika. Sweta and Jyotika cannot be with Rupali, but are in a Weight-group with total membership of four . No weight-group can have more than five or less than one member.Amita, Babita, Chandrika, Deepika, adn Elina are instructors of weight-group with membership sizes 5,4,3,2and 1,respectively. Who is the instructor of Radha ?