Hi there!
We can find the percentage by expressing the amount of oranges to total fruits as a fraction:
[tex]\text{ oranges to total fruit} = \frac{\text{x Oranges}}{\text{ y total pieces of fruit}}[/tex]
Plug in the given values:
[tex]\text{ oranges : total fruit} = \frac{\text{6}}{\text{15}} = 0.4[/tex]
Convert to a percentage by multiplying by 100:
0.4 × 100 = 40%.
[tex]\boxed{\text{40\% of total pieces of fruit are oranges}}[/tex]