All you would do is multiply .9 by 20
.9*20=18
90% of 20 is 18
To find the diameter, you use the formula: 2x. we use 2x because the radius is 2 times the diameter.
so, if the radius is 3,980, then we substitute that into the formula.
2(3,980)
this will give us 7960. the diameter is 7960 miles.
Answer: A. 724
Step-by-step explanation:
Answer: (a) 
(b) 
Step-by-step explanation:
(a) P( Bill hitting the target) = 0.7 P( Bill not hitting the target) = 0.3
P( George hitting the target) = 0.4 P(George not hitting the target) = 0.6
Now the chances that exactly one shot hit the target is = 0.7 x 0.6 + 0.4 x 0.3
= 0.54
Chances that George hit the target is = 0.4 x 0.3 = 0.12
So given that exactly one shot hit the target, probability that it was George's shot = 
= .
(b) The numerator in the second part would be the same as of (a) part which is 0.12.
The change in the denominator will be that now we know that the target is hit so now in denominator we include the chance of both hitting the target at same time that is 0.4 x 0.7 and the rest of the equation is same as above i.e.
Given that the target is hit,probability that George hit it = 
= =
Answer: 2,000 ÷ 50
Step-by-step explanation:
From the question, we are informed that John needs to write 2,146 online math questions in 45 weeks and that he is estimating how many questions he should write each week to meet the deadline.
The compatible numbers that provide a better estimate for the number of question he should write each week, is 2,000 ÷ 50. This is because rounding up of 2146 to the nearest thousand gives 2000. The number beside the thousand place is 2 and sinces it's not up to 5, the number becomes 2000. Likewise 45 to the nearest ten gives 50 since the number beside the ten is 5, therefore 1 will be added to 4 which becomes 5 and the number in the unit place is changed to 0, this makes the number become 50.
Therefore, the answer is 2000 ÷ 50.
