Answer:
8
Step-by-step explanation:
0) the basic formula is: L=v*t, where L - distance, v - speed/velocity; t - time;
1) if the person's speed in still water is 'v' and the speed of water is 5 (according to the condition), then the upstream speed is 'v-5' and the downstream speed is 'v+5';
2) according to the condition the upstream time and the downstream time are the same, it means t₁=t₂=t, where t₁=upstream time and t₂=downstream time;
3) according to the items above it is possible to make up the equation of the upstream travel: t(v-5)=3; ⇒ t=3/(v-5);
4) according to the items above it is possible to make up the equation of the downstream travel: t(v+5)=13; ⇒ t=13/(v+5);
5) if t=3/(v-5) and t=13/(v+5), then

Answer:
x = 5m/s
Step-by-step explanation:
Distance flying out = 12 km (headwind)
Distance flying back = 12 km (tailwind)
total distance = 12 + 12 =24 km
wind speed = 1km/h
speed going out (with headwind) = (x - 1) km/h
speed coming back (with tailwind) = (x + 1) km/h
Time taken to go out = distance going out / speed going out
= 12 / (x-1)
Time taken to come back = distance coming back / speed coming back
= 12 / (x+1)
total time = time taken to go out + time taken to come back
5 =[ 12/(x-1) ] + [ 12/(x-1)]
expanding this, we will get
5x² - 24x - 5 = 0
solving quadratic equation, we will get
x = -1/5 (impossible because speed cannot be negative)
or
x = 5 (answer)
Answer:
4d i think im not sure???hoped it helped?