Answer:
BCD = 60
ABD - 90
Step-by-step explanation:
BCD)
BC and CD are the same length on in the circle, they are the radius. Therefor, all angles will be the same at 60
ABD)
All angles together are 180
You know 2 Angles, A at 30 and D at 60
180 - 30 - 60 = Angle B
90 = Angle B
Answer:
(a) 0.018 dm^3
(b) 20 x 10^15 ml^3
Step-by-step explanation:
a) 18 cm^3 to dm^3
1 cm = 0.1 dm
So,
1 cm^3 = 0.001 dm^3
So, 18 cm^3 = 18 x 0.001 dm^3 = 0.018 dm^3
b) 20 hl^3 to ml^3
1 hl = 100000 ml
So, 1 hl^3 = 10^15 ml^3
So,
20 hl^3 = 20 x 10^15 ml^3.
Answer:

Step-by-step explanation:
The large mixing tank initially holds 500 gallons of water in which 50 pounds of salt have been dissolved.
Volume = 500 gallons
Initial Amount of Salt, A(0)=50 pounds
Brine solution with concentration of 2 lb/gal is pumped into the tank at a rate of 3 gal/min
=(concentration of salt in inflow)(input rate of brine)

When the solution is well stirred, it is then pumped out at a slower rate of 2 gal/min.
Concentration c(t) of the salt in the tank at time t
Concentration, 
=(concentration of salt in outflow)(output rate of brine)

Now, the rate of change of the amount of salt in the tank


We solve the resulting differential equation by separation of variables.

Taking the integral of both sides

Recall that when t=0, A(t)=50 (our initial condition)

Answer:
= 2 4/15 km
Step-by-step explanation:
Speed = 3 2/5 km/hour
The units are not the same. The speeds is in hours and the time is in minutes
Lets convert minutes to hours. 60 minutes = 1 hour
40 minutes * 1 hour/ 60 minutes = 40/60 hours = 2/3 hour
Distance = speed * time
= 3 2/5 * 2/3
Change the mixed number to an improper fraction
3 2/5 = (5*3+2)/5 = 17/5
= 17/5 * 2/3
= 34/ 15 km
Change this back to a mixed number
15 goes into 34 2 times (15*2 = 30) with 4 left over
= 2 4/15 km