What is the greatest possible speed at which a person can walk 13·3 km and 20·9 km so that the time (in hours) required in each case is a whole number?

The greatest number of four digit which is divisible by 15, 25, 40 and 75 is :

The first pair of numbers bear a certain relationship. The same relationship is required to be found in the other pair, Find that missing number : 35 : 6 : : 120 :?

Find the smallest perfect square number which is exactly divisible by 4, 5, 6, 15 and 18 :

If three times the greater of two numbers is divided by the smaller number, the quotient will be 6 and the remainder will be 6. If five times the smaller number is divided by the greater number, the…

The sum of digits of a 2-digit number is 12. When the digits are reversed, the number becomes greater by eighteen. What is the difference between the digits in the number ?