A blacksmith has five iron articles A, B, C, D and E, each having a different weight. (i) A weights twice as much as B. (ii) B weights four and a half times as much as C. (iii) C weights half as much as D. (iv) D weights half as much as E. (v) E weights less than A but more than C.
Which of the following is the lightest in weight ?
How many 7's are there in the following series which are preceded by 6 which is not preceded by 8 ? 8 7 6 7 8 6 7 5 6 7 9 7 6 1 6 7 7 6 8 8 6 9 7 6 8 7