Final answer:
By dividing the number of ballet dancers (63) by the percentage that represent ballet dancers (0.42), we determine that the total number of dancers in the dance school is 150.
Step-by-step explanation:
To find the total number of dancers in the dance school, we use the information that 42% of the total are ballet dancers, and the number of ballet dancers is given as 63. The equation to represent this situation is:
0.42 × Total number of dancers = 63
To solve for the total number of dancers, divide 63 by 0.42:
Total number of dancers = 63 ÷ 0.42
Total number of dancers = 150
Therefore, the correct answer is B. 150.