Answer:
probability that he or she will answer at least 4 problems correctly = 0.5
Step-by-step explanation:
probability that he or she will answer at least 4 problems correctly is given as;
P (at least 4 correctly) = P (exactly 4 correctly) + P (all 5 correctly)
Since there are 10 problems. 4 is from the 7 problems chosen and 1 is from the 3 problems we can't figure out. Thus, P(exactly 4 correctly) = 7C4 x 3C1
Thus, P (at least 4 correctly) = [ (7C4) x (3C1) ] / (10C5)] + [(7C5)/(10C5)]
= [(35 x3)/252 ] + [21/252]
= [ 105/252 ] + [ 21/252 ]
= 126 / 252
= 0.5
Volume = π×22<span>×6 = </span><span>75.398223686155 feet^3</span>
Answer:
0
Step-by-step explanation:
i think sorry if wrong
5 100ml cups and 1 500 ml cup
and 2 500 ml cups
Newton's Law of Cooling
Tf=Ts+(Ti-Ts)e^(-kt) where Tf is temp at time t, Ts is temp of surroundings, Ti is temp of object/fluid. So we need to find k first.
200=68+(210-68)e^(-10k)
132=142e^(-10k)
132/142=e^(-10k)
ln(132/142)=-10k
k=-ln(132/142)/10
k≈0.0073 so
T(t)=68+142e^(-0.0073t) so how long until it reaches 180°?
180=68+142e^(-0.0073t)
112=142e^(-0.0073t)
112/142=e^(-0.0073t)
ln(112/142)=-0.0073t
t= -ln(112/142)/(0.0073)
t≈32.51 minutes
