Answer:
1.555711807*10^10
Step-by-step explanation:
It's D. 311 divided by 12 is 25.9
Cosα=x/L
L=x/cosα, we are told that the ladder base is 48 ft from the base of the wall and α=39° so:
L=48/cos39 ft
L≈61.76 ft (to nearest hundredth of a foot)
To make it easier convert the times all into minutes.
2 hours 20 minutes = 120 minutes + 20 minute = 140 minutes
4 hours 10 minutes = 240 minutes + 10 minutes = 250 minutes
Then subtract:
250 minutes - 140 minutes = 110 minutes
Convert back to hours/minutes:
110 minute = 1 hour and 50 minutes