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
Let the consecutive even numbers be A = 2x, B = 2x + 2, C = 2x + 4, D = 2x + 6 and E = 2x + 8= A + B + C + D + E = 130= 10x + 20 = 130∴ x = 130 - 20/10 = 11Therefore, product of A and E= 22 x 30 = 660
Let the middle digit be x. Then, 2x = 10 or x = 5.So, the number is either 253 or 352. Since the number increases on reversing the digits, so the hundred's digit is smaller than the unit's digit. Hence, required number = 253.