The ratio of the number of ladies to that of gents at a

The ratio of the number of ladies to that of gents at a party was 3 : 2. When 20 more gents joined the party, the ratio was reversed. The number of ladies present at the party was

Let the number of ladies and gents be 3x and 2x respectively.
According to the question,

3x	=	2
2x + 20	=	3

⇒ 9x = 4x + 40 ⇒ 5x = 40
⇒ 9x = 4x + 40 ⇒ 5x = 40
⇒ x = 8
∴ Number of ladies = 3x
= 3 × 8 = 24