A7-digit number has a in the ones place a 6 in the ten thousands place and 8 in the millions place and 5 and each other remaining places what is the number

answer: 4  

the square root of 16 is 4. it is a very simple mathematic concept. a square root when a number multiplied by itself will result in a number. here, the number 16 comes when 4 is multiplied by 4. hence the square root of 16 is 4. you can always figure out a square root by the inverse operation of squaring.