She has to pay £100.98.
Explanation:
Given,
The cost of adult ticket = £12
The cost of child ticket = £6
10% booking fee will be added.
2% will be added if she is paying by credit card.
Number of adult = 6
Number of child = 3
To find the cost of ticket if she uses her credit card.
Formula
If a% increases on b the value will be = b×
Total cost of the ticket = £12×6+£6×3 = £90
After 10% booking fee = £90×
= £99
After paying by her credit card 2% = £99×
= £100.98
Hence,
She has to pay £100.98.