What kind of letter is used for recessive traits

Lower case letters are used for recessive traits

In biology, a trait or character is a feature of an organism.  A trait refers to any genetically determined characteristic in the body. In technical terms, a genetic trait is amenable to segregation analysis rather than quantitative analysis.  Recessive traits are those that are expressed only when two copies of an allele are present in the gene.

The correct answer is 15%.

Explanation:

In a bag of fertilizer, the letters NPK is written, which signifies nitrogen content, phosphorus content, and potassium content in sequential order. These are the three nutrients that form a complete fertilizer. The content of the nutrients is denoted by numbers, which is followed by a percentage symbol as these numbers signify the percentage of the nutrient in the formation of the fertilizer. Thus, 30-15-10 shows that the given fertilizer comprises 30 percent nitrogen, 15 percent phosphorus, and 10 percent potassium.