Saved Bookmarks
| 1. |
How many numbers between 6000 and 7000 formed with the digits 0, 1, 5,6, 7 and 9 are divisible by 5 if(i) repetition of digits is allowed(ii) repetition of digits is not allowed |
|
Answer» (i) Unit's place only 0,5 can be placed - 2 ways. Ten's place all number can be placed - 10 ways. Hundred's place all number can be placed - 10 ways. Thousand's place only 6 can be placed - 1 way. total ways =2×10×10=200. (ii) Clearly, thousands digit is 6. Number of numbers with units digit 0=(1×8×7×1)=56 Number of numbers with units digit 5=(1×8×7×1)=56 Required number of numbers=(56+56)=112. |
|