3 apples and a pineapple equally balances 10 oranges. Also,6 oranges and an apple equally balances a pineapple. How many oranges balance a pineapple?

3 a + p = 10 o

6 o + a = p write as 3 a + 18 o = 3 p

so now
3 a + p = 10 o
3 a + 18 o = 3 p
------------------subtract
p - 18 o = 10 o - 3 p

4 p = 8 0
1 p = 2 o
so
two oranges balance a pineapple

Let's assume the number of oranges required to balance a pineapple is 'x'.

According to the first scenario, 3 apples and a pineapple equally balance 10 oranges.

This can be expressed as (3 apples + 1 pineapple) = 10 oranges.

Now, let's consider the second scenario, where 6 oranges and an apple equally balance a pineapple.

This can be expressed as (1 apple + 6 oranges) = 1 pineapple.

Since both scenarios involve balancing a pineapple, we can equate the two expressions:

(3 apples + 1 pineapple) = (1 apple + 6 oranges)

By rearranging the terms, we get:

(3 apples - 1 apple) = (6 oranges - 1 pineapple)

Simplifying further, it becomes:

2 apples = 6 oranges - 1 pineapple

Now, let's substitute the value of apples in terms of oranges from the first scenario:

2(10 oranges - 1 pineapple) = 6 oranges - 1 pineapple

Expanding and rearranging the equation, we get:

20 oranges - 2 pineapples = 6 oranges - 1 pineapple

Combining like terms, we have:

20 oranges - 6 oranges = 1 pineapple - 2 pineapples

14 oranges = -1 pineapple

Since the number of oranges cannot be negative, this implies that there is no solution to this system of equations. Hence, we cannot determine the exact number of oranges that balance a pineapple based on the given information.

To solve this problem, we need to set up a system of equations. Let's assume that "x" represents the number of oranges needed to balance a pineapple.

From the first statement, we know that 3 apples and a pineapple equally balance 10 oranges. This can be written as:

3 apples + 1 pineapple = 10 oranges

From the second statement, we know that 6 oranges and an apple equally balance a pineapple. This can be written as:

6 oranges + 1 apple = 1 pineapple

Now we have a system of two equations:

Equation 1: 3 apples + 1 pineapple = 10 oranges
Equation 2: 6 oranges + 1 apple = 1 pineapple

To solve this system, we can use substitution.

From Equation 2, we can solve for the number of apples:
1 apple = 1 pineapple - 6 oranges

Now we substitute this value into Equation 1:

3(1 pineapple - 6 oranges) + 1 pineapple = 10 oranges

Expanding the equation:
3 pineapples - 18 oranges + 1 pineapple = 10 oranges

Combining like terms:
4 pineapples - 18 oranges = 10 oranges

Moving all the terms with oranges to one side:
4 pineapples = 28 oranges

Dividing both sides by 4:
pineapples = 7 oranges

Therefore, a pineapple balances 7 oranges.