On planet korba, a solar blast has melted the ice caps on its equator. 9 years after the ice melts, tiny
planetoids called echina start growing on the rocks. Echina grows in the form of circle, and the relationship
between the diameter of this circle and the age of echina is given by the formula d = 4*S (t-9) for t T 9 where d
represents the diameter in mm and t the number of years since the solar blast.Jagan recorded the radius of
some echina at a particular spot as 7mm. How many years back did the solar blast occur?
a) 17 b)21.25 c)12.25 d)14.05

• whats S??????
  
• 8 years agoHelpfull: Yes(2) No(0)
• umm I don't know if s stands for square root, if that's the case, answer will be B i.e. 21.25
• 8 years agoHelpfull: Yes(2) No(0)
• some fonts in the question are meaningless, so it is difficult to understand the meaning clearly. If we consider the meaning as d = 4*(t-9) then according to the given condition r = 7 mm so diameter = 14 mm, on putting d = 14, we get
  14 = 4*(t-9) or 3.5 = t-9 or t = 12.5
  
  Read more at http://www.m4maths.com/1707-On-planet-korba-a-solar-blast-has-melted-the-ice-caps-on-its-equator-9-years-after-the-ice-melts.html#Gj9u20djiADzMxHX.99
• 8 years agoHelpfull: Yes(2) No(1)
• b
  given that r=7mm,so d=14mm susstitute this in equation gives the solution
• 8 years agoHelpfull: Yes(1) No(1)
• did you qualify email??
• 8 years agoHelpfull: Yes(1) No(0)
• Option : C is the right answer
• 8 years agoHelpfull: Yes(1) No(0)
• ya... nothing about " S" .. lol question
• 8 years agoHelpfull: Yes(0) No(0)