Let the greater and the smaller number be g and s respectively.gs = 2560g + s exceeds g - s by 64 i.e., g + s - (g - s) = 64i.e., 2s = 64 => s = 32.g = 2560/s = 80.
S.P. per metre = 8200/40 = Rs. 205∴ C.P. per metre = Rs. (205 - 25) = Rs. 180∴ C.P. of 40 metre cloth= Rs. (40 x 180) = Rs. 7200∴ Gain = Rs. (8200 - 7200) = Rs. 1000