Total triathlon distance →1.5 km + 40km + 10 km = 51.5 km
So 51.5 km represents 100% of distance covered.
The % of each component = (distance of component/Total distance) multiplied by 100% so :
% of swim → (1.5 / 51.5) × 100 → 0.029 × 100 = 2.9%
% of bike ride → (40 / 51.5) × 100 →0.776 × 100 = 77.6%
% of run → (10 / 51.5) × 100 → 0.194 × 100 = 19.4%
Percentage spent on land will be
(40 km bike ride + 10 km run / Total triathlon distance) multiplied by 100%
(50 / 51.5) × 100 → 0.970 ×100 = 97%