We need to convert the weight into Newtons

 

150,000 kgs X 10m/s2 (gravitational constant) = 1,500,000 N

 

L/D ration is 14:1 so the drag will be 1,500,000 / 14 = 107142.85N

 

Substitute values in formula

 

T-D/W = SINTHETA x 100 (to express as a percentage)

 

300000 -107142.85/1500000 = 0.1285714 X 100

 

= 12.86%