The ratio of the number of left-handed batters to the number of right handed batters is 5: 8. there are 45 left-handed batters. find the ratio of the number of left handed batters to the total number if batters?

FIRST YOU FIND THE TOTAL NUMBER OF RIGHT-HANDED BY DOING 
 5:8 = 45:x
 CROSS MULTIPLY : 5x = 45(8)
                                   5x = 360
                                      x = 360/5
                                       x = 72
THE TOTAL NUMBER OF BATTERS = 45 + 72 =117

THE  RATIO OF LEFT-HANDED BATTERS TO THE TOTAL NUMBER OF BATTERS IS 45/117 ( YOU CAN SIMPLIFY BOTH BY 9 ); 45/117 = 5/13.
 
      HOPE THIS HELPED

B. 2 1/2 feet. multiply 2.5 inches by 12 to get thirty inches then divide by 12 to get 2.5 feet