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
When multiplying numbers with significant digits, count the total number of significant digits in each number. Multiply the numbers as usual, but round the final answer to match the least number of significant digits in the original numbers.
Reverse the digits then check of the new number is the same as the original number.
To total 17 the two digits must be 8 and 9! The original number was 98.
The 11 finger trick is a math trick where you can quickly multiply numbers by 11. To use the trick, you separate the digits of the number you want to multiply by 11, add the two digits together, and place the result in between the original digits. This works because 11 is the same as 10 1, so when you add the two digits together and place the result in between, you are essentially multiplying the original number by 10 and then adding the original number to it.
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.
The 11 finger trick is a mental math technique where you can quickly multiply numbers by 11. To use this trick, you separate the digits of the number you want to multiply by 11, add the digits together, and place the sum in the middle of the original number. This allows you to calculate the product of the original number and 11 without using traditional multiplication methods.
by moving each digits