Answer: a. 10%
Step-by-step explanation:
Girls in the class = 40%
Girls play tennis = 25%
Percentage of class play tennis = 40%*25% = 0.4*0.25 = 0.1
Percentage of class play tennis = 10%
Answer:
165km
Step-by-step explanation:
If Gina leaves now and drives at 66km/h she will reach Alton just in time for her appointment
Now:
Distance=Speed X Time
D=66 X t=66t.....(I)
If she leaves in 40 minutes,and she must get there at the same time, her new drive time will be:
t hours - 40 minutes
=(t-40/60)hours=( t-2/3) hours
Her Distance this time
D=90(t-2/3)=90t-60.....(ii)
Since the distance to Alton does not change, we equate (I) and (ii)
66t=90t-60
60=90t-66t
60=24t
t=2.5 hours
From equation (I)
Distance=66t=66X2.5=165km
Distance to Alton is 165km.
Given that Trent's watch runs at half the speed it should run, this implies that
for every hour passed, his watch moves by half an hour.
Hence, for every half-hour passed, Trent's watch moves by 15 minutes.
Hence, when the real time is 10:30 am, Trent's watch will show 9:15 am.
Sin x = cos (90-x)
eg sin 42 = cos(90-42) = cos 48
so the answer is B