Answer:
108 people
Step-by-step explanation:
Number of successes
=(Number of test subjects) X (Success rate)
=285*(38%)
=285*0.38
= 108.3 => 108
Therefore there were 108 successes among 285 trials.
Label your unknown numbers
I'm calling them x and y
x+y=21
5x+2y=66
find a relation of x and y
y=21-x
substitute this into your second equation
5x+2 (21-x)=66
simplify to find x
5x+42-2x=66
3x+42=66
3x=24
x=24/3=8
apply your findings to find the second number
8+y=21
y=13
check your answer
5 (8)+2 (13)=66
40+26=66
we now know that the first number x is 8
and the second number y is 13
Answer:
Step-by-step explanation:
You ask a neighbor to water a sickly plant while you are on vacation. Without water the plant will die with probability 0.7. With water it will die with probability 0.4. You are 86 % certain the neighbor will remember to water the plant.
Prob for plant dying with water = prob that he waters but plant dies
= 0.86*0.4
= 0.344
Prob for plant dying without water = prob that he does not water and the plant dies
= (1-0.86)*0.7
= 0.098
Answer:
26
Step-by-step explanation:
182 pencils devided by 7 identical boxes
182÷7
=26 pencils are in each box