poorvi

Given that the number 1372x413 is divisible by 11, where x is a digit, then the value of x is To find if number is divisible by 11, difference of sum of digits at even places and sum of digits at odd places should be either 0 or 11. is this correct?????

a b c = 100 a + 10 b + c a = 2 c reversed c b a = 100 c + 10 b + a 100 a + 10 b + c - 100 c - 10 b - a = 396 99 a - 99 c = 396 but a = 2 c so 198 c - 99 c = 396 99 c = 396 c = 4 then a = 8 b might be 1 or 3 however the difference is same

Zinc in 2 kg of new alloy = (5/13 + 5/8) = 105/104 kg copper in 2 kg of new alloy = (8/13 + 3/8) = 103/104 kg Ratio of zinc and copper in new alloy = 105/104 : 103/104 = 105:103 hope this example helps.....