Step-by-step explanation:
Let the amount of apples bought be x
Amount of strawberries bought be y and;
amount of oranges bought be z
If we buy 2 apples, 3 boxes of strawberry, and 4 oranges, the fruit would cost $15.30, then this will be expressed as;
2x+3y+4z = 15.30 ........... 1
If we buy 1 box of strawberry, 4 apples, and 2 oranges, the fruit would cost $10.90, this will be expressed as:
4x+y+2z = 10.90 ......... 2
If we buy 1 orange, 5 apples and 2 boxes of strawberry, the fruit would cost $13.70, this is expressed as:
5x+2y+x = 13.70 .......... 3
Solving the three equations simultaneously:
2x+3y+4z = 15.30 ........... 1
4x+y+2z = 10.90 ......... 2
5x+2y+z = 13.70 .......... 3
Reduce the number of equations
multiply equation 1 by 2 and subtract from equation 2
equation 1 * 2 will give:
4x+6y+8z = 30.6 ........... 4
eqn (4)-eqn(2)
6y-y + 8z-2z = 30.6-10.90
5y+6z = 19.7 ......... 5
Also multiply equation 2 by 5 and eqn 5 by 4 and subtract from each other.
eqn(2)* 5 will give:
20x+5y+10z = 54.5 .......... *
eqn(3) * 4 will give
20x+8y+4z = 54.8.......**
Subtsrct ** from *
8y-3y+(4z-10z)= 54.8-54.5
5y-6z = 0.3 .................. 6
Equate 5 and 6 and solve:
5y+6z = 19.7 ......... 5
5y-6z = 0.3 .................. 6
subtract:
6z+6z = 19.7+0.3
12z = 20
z = 20/12
z = 1.67
Substitute z = 1.67 into eqn 6
5y-6(1.67) = 0.3
5y - 10 = 0.3
5y = 10.3
y = 10.3/5
y = 2.06
Substitute z = 1.67 and y = 2.06 into equation 1
From 1:
2x+3y+4z = 15.30
2x+3(2.06)+4(1.67) = 15.30
2x+6.18+6.68 = 15.30
2x+12.86 = 15.30
2x = 15.30-12.86
2x = 2.44
x = 2.44/2
x = 1.22
<em>Therefore 1 apple costs $1.22, 1 strawberry costs $2.06 and 1 orange costs $1.67</em>
= 1/3. The answer is letter C.