Basic applied math -- can't find a solid answer, please help

[rpd73080]

[/b] I am looking to find the confirmed answer of an applied math problem and how to solve it. Can someone please help? I have come up with three answers for this problem, and I'm not sure which one is the right one!

An aircraft has flown 375 miles in 90 minutes. What is the aircraft's ground speed?

A. 150 kts
B. 200 kts
C. 250 kts
D. 300 kts

 

[tkhunny]

Miles? What kind?

375 nautical miles / 90 minutes = 375/1.5 kts = 250 kts

375 statute miles / 90 minutes = (375/1.15)/1.5 kts = 217 kts

 

[rpd73080]

Miles? What kind?

375 nautical miles / 90 minutes = 375/1.5 kts = 250 kts

375 statute miles / 90 minutes = (375/1.15)/1.5 kts = 217 kts

Yes, nautical miles... I am wondering where the 1.5kts comes from though, or is this 1.5 hours?

 

[stapel]

You're asked for a speed. I can't see your book, so I can't be sure, but if the answer options are all given in "knots", presumably your book discussed knots and wants the answer stated in terms of this unit. So you might want to review that section.

"Hours" is a unit of time, not of speed, so the answer for "speed" is unlikely to be "1.5 hours".

Eliz.