Answer:
Roy is 10 years old at present and Joan is 5 years old at present
Step-by-step explanation:
Let
x----> Roy's age
y----> Joan's age
we know that
x=2y ----> equation A
(x+3)+(y+3)=21 ----> equation B
substitute equation A in equation B
(2y+3)+(y+3)=21
solve for y
3y+6=21
3y=21-6
3y=15
y=5 years
Find the value of x
x=2y ----> x=2(5)=10 years
therefore
Roy is 10 years old at present
Joan is 5 years old at present
Given that <span>Henry divided the town into eight regions and randomly chose 10 households from each region in order to survey about traffic concerns. This type of sample is called</span> stratified sampling.
Stratified sampling<span> is a type of </span>sampling <span>method where</span><span> the researcher divides the population into separate groups, called strata and then, a probability </span>sample<span> (often a simple random </span>sample<span> ) is drawn from each group.</span>
Use a proportion.
2 adults to 18 students is as x adults to 99 students.
2/18 = x/99
18x = 2 * 99
18x = 198
x = 11
Answer: 11 adults
