Q) Mr Yang's son has a total of twenty-one $1 and $2 coins in his money box. When he counts his money, he finds that it's total value is $30. How many coins of each type does he have?

Well, it sounds like Mr. Yang's son has got some serious monetary confusion going on. But fear not, for I, Clown Bot, have arrived to solve this riddle!

Let's break it down with some clown math. We know he has a total of twenty-one coins. So, let's say he has "x" number of $1 coins, and "y" number of $2 coins.

Now, the total value of all the coins is $30. That means we can set up an equation: 1x + 2y = 30.

Since we also know that he has a total of twenty-one coins, we can set up another equation: x + y = 21.

Now it's time for some clown algebra magic! Let's solve the system of equations and find our answer.

Multiply the second equation by 2: 2x + 2y = 42.

Subtract the first equation from the multiplied second equation: (2x + 2y) - (1x + 2y) = 42 - 30.

Simplify: x = 12.

Now we can substitute this value of "x" back into one of the original equations to find the value of "y". Let's use the second equation: 12 + y = 21.

Solving for "y", we find that y = 9.

So, according to my calculations, Mr. Yang's son has 12 $1 coins and 9 $2 coins. Now he just needs to avoid any monetary mix-ups with his money box!

Let's assume the number of $1 coins as 'x' and the number of $2 coins as 'y'.

According to the given information, we have two equations:

1. The total number of coins is 21:
x + y = 21 ---(Equation 1)

2. The total value of the coins is $30:
1x + 2y = 30 ---(Equation 2)

To solve this system of equations, we can use the method of substitution or elimination.

Let's use the elimination method to solve the system:

Multiply Equation 1 by 2 to make the coefficients of 'y' in both equations equal:
2x + 2y = 42 ---(Equation 3)

Now, subtract Equation 2 from Equation 3 to eliminate 'y':
(2x + 2y) - (1x + 2y) = 42 - 30
2x + 2y - x - 2y = 12
x = 12

Substituting the value of x back into Equation 1:
12 + y = 21
y = 21 - 12
y = 9

Therefore, Mr. Yang's son has 12 $1 coins and 9 $2 coins.

To solve this problem, you can use a system of equations. Let's say the number of $1 coins is x, and the number of $2 coins is y.

We can start by setting up two equations based on the given information:

Equation 1: x + y = 21 (The total number of coins is 21)
Equation 2: 1x + 2y = 30 (The total value of the coins is $30)

To solve this system of equations, you can use substitution or elimination. Let's use elimination:

Multiply Equation 1 by 2 to make the coefficients of y the same in both equations:

2x + 2y = 42

Now subtract Equation 2 from this:

2x + 2y - (1x + 2y) = 42 - 30
x = 12

Now substitute the value of x into Equation 1:

12 + y = 21
y = 9

So, Mr. Yang's son has 12 $1 coins and 9 $2 coins.

o + t = 21

1 o + 2 t = 30

subtracting equations

t = 9