Answer:
He will finish the rest of the problems in 32.4 minutes.
Step-by-step explanation:
Since we are given that Yan has completed 3/5 of 45 problems i.e.


Thus he has completed 27 problems
Remaining no. of problems are 45-27 = 18
Since he complete each problem in minutes = 
So, he completes 18 problems in minutes = 18 *1.8 = 32.4 minutes
Hence , He will finish the rest of the problems in 32.4 minutes.
Answer:
12
Step-by-step explanation:
Let the slower runners speed be X kilometers per hour.
Then the faster runners speed would be X+2 kilometers per hour.
The formula for distance is Speed times time.
The distance is given as 30 kilometers and time is given as 3 hours.
Since there are two runners you need to add the both of them together.
The equation becomes 30 = 3x + 3(x+2)
Now solve for x:
30 = 3x + 3(x+2)
Simplify:
30 = 3x + 3x +6
30 = 6x + 6
Subtract 6 from each side:
24 = 6x
Divide both sides by 6:
x = 24/6
x = 4
The slower runner ran at 4 kilometers per hour.
The faster runner ran at 4+2 = 6 kilometers per hour.
The whole thing flips around and ends up being t = 3k/?