A is 40% more efficient than B and both can complete a work in 20 days. A and B start work and do it for eight day. If remaining work is complete by C in 24 days, then find in how many days C will complete work alone?

A and B ratio of efficiency = 140x : 100x

= 7x : 5x

Total work = 20 (7x + 5x) = 240x units

A and B is eight days = 8 ×(7x + 5x) = 96x units

Efficiency of C = $frac{{240x - 96x}}{{24}} = frac{{144x}}{{24}} = 6x;{ m{units/day}}$

C alone = $frac{{240x}}{{6x}} = 40;{ m{days}}$