Hi Toni, 
Really sorry, that's my fault for putting the numbers in a confusing way. To be clear: 
There are 15 people booked on the main trip, 6 men and 9 women. Their ages range from late 50s to late 70s. 
8 people from that group are also doing the add-on, 3 men and 5 women. 
I hope that makes sense now, apologies for the confusion. 
Thanks,
Vickie