V1=30km/hr
v2=20km/hr
v=2v1v2/(v1+v2)
=2*30*20/(30+20)
=24km/hr
Answer:
1/3 of 3 hours should be 20 minutes
Y and x are directly proportional, as stated by hypothesis. Let's use the rule of three to find y when x = 8.
x=5 --> y=12
x=8 --> y=?
? = (8*12)/5 = 96/5 = 19.2
So y directly varies with x, and y=12 when x = 5, then y=19.2 when x=8.
Hope this Helps! :D