what percentage of numbers from 1 to 60 have 1 or 9 in the unit ' s digit ?
"clearly , the numbers which have 1 or 9 in the unit ' s digit , have squares that end in the digit 1 . such numbers from 1 to 60 are 1 , 9 , 11 , 19 , 21 , 29 , 31 , 39 , 41 , 49 , 51 , 59 number of such number = 11 answer : c"
multiply(divide(multiply(const_2, divide(60, const_10)), 60), const_100)