At first, the ratio of the number of men to the number of women in a fun fair was 4:5. When 36 woman and some men joined in the fun fair, there was a 12% increase in the number of women and the total number of people was increased by 20%.

a) How many men were there at first?

b) What was the percentage in crease in the number of men after 36 women and some men joined in the fun fair?