20. In 1911 a French Physicist Paul devised a thought experiment based on Einstien’s Special Relativity. In the experiment, a person makes a journey into space at nearly speed of light and comes back to earth. He finds that he has aged five times less than his twin who stays back on earth for 40 years. This is popularly known as the twins paradox. Now consider the case of Hansel and Gretel, who are not twins five years ago. Hansel was twice as old as was Gretel. If they journey in to space, and automatic clock assists in logging the start time of their journey accurately. If the do not journey in to space, 5 years hence Hansel age will be 4/3 times the age of Gretel. Find Hansel’s age today in binary numbers.

• 5 years ago, Age of Gretel = 5 yrs , Age of Hansel = 10 yrs
  Now Age of Gretel = 10 yrs , Age of Hansel = 15 yrs
  5 years later, Age of Gretel = 15 yrs , Age of Hansel = 20 yrs
  
  Age of Hansel now in binary code = 1111
• 13 years agoHelpfull: Yes(3) No(0)
• (h-5)=2(g-5)....1
  (h+5)3=(g+5)4....2
  nw solve it h=15 n g 20
  so binary of 15 =1111
• 13 years agoHelpfull: Yes(2) No(1)