Question

Find the least square number exactly divisible by each one of the numbers 6 9 15 20​

Answer 1

Answer:

900

Step-by-step explanation:

divisibility rules for 6,9,15 and 20 are

6 : to be divisible by 2 and 3

      2 : unit digit should be even

      3 : sum of the digits in given number should be divided by 3

9 : same as 3

15: to be divided by 3 and 5

      5 : unit digit must contain 0 or 5

20: all are multiples of 2 and containing 0 in its unit digit

common rule is 0 in units place

the square numbers which are satisfying this condition are

100,400,900,1600 and so on

900 is the least square number which satisfies all the above rules