Original number is 1000a + 100 b + 10c + d, and a must be 2, If it were 3 or more then multiplying be 4 would give a 5-digit number, and it can't be 1 because it is the units figure in the multiplied number and 1 can't be the last digit in a multiple of 4.
Similarly d must be 3 or 8 to give a number ending in 2 when multiplied by 4,and can't be 3 'cos no multiple of 4 ends in a 3...
Four times original is 4000a + 400b + 40c +4d which equals 1000d + 100c + 10b + a
so 3999a + 390b = 60c + 996d which simplifies to
1333a + 130b = 20c + 332d.
a = 2, d = 8, then 20c - 130b = 2666 - 2656.
20c - 130b = 10 so c = 7 and b = 1
The original number is 2178 (x 4 = 8712)
Whew!
Possibility of two digit no whose sum is 11 Are 29,38,47,56,65,74,83,92 Subract 45 to each no mentioned above -16,-7,2,11,20,29,38,47 See after 6th comma 83 and 38 Reverse of 83 is 38. The no 38 is 45 less than 83. Original no is=83
Possibility of two digit no whose sum is 9 18,27,36,45,54,63,72,91 Now add 9 to each no mentioned above 27,36,45,54,63,72,91,100 See after third comma 45 and 54. If you reverse 45 it will be 54. which is 9 more than 45. So original no is 45
The number is 36
First you subtract the new number from the original number then divide it by the original number and multiply that by 100 original-new __________*100 original
The usual case is when you multiply or divide an inequality by a negative number.
2178 x 4 = 8712
whats the answer please??
38
Reverse the digits then check of the new number is the same as the original number.
Possibility of two digit no whose sum is 17 89 and 98 Reverse of 89 is 98. 98 is 9 less than the original no 89. 89 is original no
Multiply the last digit by 7. Subtract that number from the remaining digits. If that number is divisible by 23, then the original number is divisible by 23.
five digits number when you multiply by four is the same the number when you reversed it is 21978*4 = 87912
the number one.
by moving each digits
The most efficient method is to reverse the digits in the number and then check if the reversed number is equal to the original number. In C, we can implement this as follows (using long-hand notation for clarity). Note the use of base (defaulting to base 10) so that we can check values in other bases. bool is_palindrome (unsigned num, unsigned base = 10) { // local variables unsigned rev, digit, digits; // copy the input number digits = num; // initialise the accumulator rev = 0; // repeat while there are digits while (digits) { // extract the low-order digit using modulo (%) operator digit = digit % base; // shift the accumulated digits (if any) one position to the left rev = rev * base; // add on the new digit rev = rev + digit; // shift the remaining digits one position to the right digits = digits / base; } // end while // return true if the number and its reverse are equal return num == rev; }
Possibility of two digit no whose sum is 10 19,28,37,46,55,64,73,82,91 Now add 54 to each no mentioned above 73,82,91,100,109,118,127,136,145 See after 1st comma 28 and 82 Reverse of 28 is 82. That no 82 is 54 more than the no 28. So 28 is the original
The easiest way is to multiply the original number by 1.08. Otherwise, multiply the original number by .08 and add the resulting number to the original number.