The diploid number of the fern and onion plants are
fern: 1010
onion plant: 16
The formula of the diploid is 2N where N represents the haploid number.
Diploid = 2N ;
fern:
1010 = 2N
1010/2 = N
505 = N ;
onion plant:
16 = 2N
16/2 = N
8 = N
The haploid number for the fern is 505 and the haploid number for the onion plant is 8.