I think it would be the last one. I hope this helped!
Answer:
Hence, 3,40,000 can be expressed as 
Step-by-step explanation:
Step 1 of 1
Consider 3,40,000
3.4
So, 3.4 lies between 1 & 10
Now, Decimal has moved 5 places to left.

So, 3,40,000=
The actual speed of the plane with the wind:
v² = ( 150 + 50 · cos 45°)² + ( 50 · sin 45°)²
v² = ( 150 + 35.355 )² + 35.355²
v² = 34,356.467 + 1,249.976
v = √35,606.452
v = 188.7 mph
D, because 1/4 is equivalent to 4/12 and 7/12+4/12=11/12 which is equivalent to 5/6