For Type A: 10kg/1.25kg = 8 bags, therefore for 10kg it costs 8 x £1.50 = £12.00.
For Type B: 1 bag used to cost £6.60 but now has 15% off =>15% of £6.60 => £6.60 x 0.15 = £0.99 => So one bag now costs £6.60-£0.99=£5.61. 10kg/5kg = 2 bags, therefore for 10kg it costs 2 x £5.61 = £11.22.
ANSWER: 10Kg of Type B is cheaper at £11.22