I tried doing this problem but i just don't get it:

A boy has 16 coins consisting of nickles, dimes, and quarters. The number of nickles is 3 less than the number of dimes and the value of the quarters is 55 cents greater than the value of the dimes. How many coins of each kind has he?

2) If three pipes are all opened, they can fill an empty swimming pool in 3 hours. The largest pipe alone takes one third the time that the smallest pipe takes and half the time the other pipe takes. How long will each pipe take by itself.

1)

N+D+Q=16
N=D-3
.25Q-.55=.10D

2)
remember Distance=rate*time? It applies here, let volume=rate*time

time= volume/rate
3hrs=volume/(Largestrate + otherrate+smallerrate)

but Largestrate=3*smallestrate
and largestrate=2*otherrate
so
3=volume/(largestrate+1/2 largestrate+1/3s largestrate)

11/6 largest rate=1/3 volume
largest rate= 2/11 volume or the largest pipe can empty the pool in 11/2 of an hour or 5.5 hrs.

a boat weighs 1500 lb more than its motor and 1900 lb more than its trailer. Together the boat and the motor weigh five times as much as the trailer. how much does the baot weigh?

To solve these types of problems, you'll need to set up a system of equations based on the given information. Let's work through each problem step by step:

1) Let's start by assigning variables to the unknowns. Let's say the number of nickels is "n," the number of dimes is "d," and the number of quarters is "q." According to the problem, we know:

- The number of nickels is 3 less than the number of dimes: n = d - 3
- The value of the quarters is 55 cents greater than the value of the dimes: 25q = 10d + 55

We also know the total number of coins: n + d + q = 16

Now we have a system of three equations based on the given information:

n = d - 3
25q = 10d + 55
n + d + q = 16

2) Similarly, let's assign variables to the unknowns. Let's say the time taken by the largest pipe is "L," the time taken by the smallest pipe is "S," and the time taken by the other pipe is "O." According to the problem, we know:

- The largest pipe takes one third the time that the smallest pipe takes: L = (1/3)S
- The largest pipe takes half the time the other pipe takes: L = (1/2)O

We also know that if they all work together, they can fill the swimming pool in 3 hours: 1/L + 1/S + 1/O = 1/3

Now we have a system of three equations based on the given information:

L = (1/3)S
L = (1/2)O
1/L + 1/S + 1/O = 1/3

To solve these systems of equations, you can use different methods such as substitution, elimination, or matrices. Let me know if you would like help with solving them using a specific method.