The average of thirteen numbers is 47. The average of the first three numbers is 39 and that of the next seven numbers is 49. The 11th number is two times the 12th number and 12th number is 3 less than the 13th number. What is the average of 11th and 13th numbers?
तेरह संख्याओं का औसत 47 है | पहली तीन संख्याओं का औसत 39 है तथा अगली सात संख्याओं का औसत 49 है | 11वीं संख्या 12वीं संख्या से दोगुनी है तथा 12वीं संख्या 13वीं संख्या से 3 कम है | 11वीं और 13वीं संख्याओं का औसत ज्ञात करें |

Options

A. 57
B. 54.5
C. 56
D. 55.5

Answer

A