Answer:
4 hours
Step-by-step explanation:
Ratio of working together
Job : number of hours
1 : 3 = 1/3
Trainer
Job : number of hours
1 : x = 1/x
Trainee
Job : number of hours
1 : 3x = 1/3x
1/x + 1/3x = 1/3
Multiply through by 3x
3x(1/x) + 3x(1/3x) = 3x(1/3)
3 + 1 = x
4 = x
x = 4 hours
It takes the trainee 4 hours to finish the job
Answer:
35/100
Step-by-step explanation:
You have to find how many juniors there are, so if you add 13, 20, and 2 you get 35. For the denominator you have to find the total number of students, so just add all of the numbers together to get 100. So there is a 35/100 chance that a randomly selected student is a junior.
The next term is 1.4 larger than the one before it, so the appropriate choice is

_____
However, the description

also correctly describes the relationship between a1 and a2, for example. While this equation is technically correct, it is less useful to work with, so is probably not the expected answer.
To find the the amount of how much the stadium is cleaned you can
The answer to this question would be: p+q+r = 2 + 17 + 39= 58
In this question, p q r is a prime number. Most of the prime number is an odd number. If p q r all odd number, it wouldn't be possible to get 73 since
odd x odd + odd= odd + odd = even
Since 73 is an odd number, it is clear that one of the p q r needs to be an even number.
There is only one odd prime number which is 2. If you put 2 in the r the result would be:
pq+2= 73
pq= 71
There will be no solution for pq since 71 is prime number. That mean 2 must be either p or q. Let say that 2 is p, then the equation would be: 2q + r= 73
The least possible value of p+q+r would be achieved by founding the highest q since its coefficient is 2 times r. Maximum q would be 73/2= 36.5 so you can try backward from that. Since q= 31, q=29, q=23 and q=19 wouldn't result in a prime number r, the least result would be q=17
r= 73-2q
r= 73- 2(17)
r= 73-34=39
p+q+r = 2 + 17 + 39= 58