find the least square number exactly divisible by each one of the number 6,9,10,15 and 20
Answers
Answer:
900
Step-by-step explanation:
LCM of 6,9,10,15,20 = 180
Since the square number is divisible by 6,9,10,15,20, it is divisible by 180 also.
180 = 2^2 × 3^2 × 5
Hence, 5 is the least number to be multiplied to 180 to make it a perfect square.
Therefore, answer = 180 × 5 = 900
Answer:
Step-by-step explanation:
ok if this helps
Divisibility by 6: The number should be divisible by both 2 and 3.
Divisibility by 9: The sum of digits of the number must be divisible
by 9.
Divisibility by 10: The number should have 0 as the units digit.
Divisibility by 15: To be divisible by 15 a number has to be divisible by 3 and by 5. To be divisible by 5 the number must end in a 0 or a 5, easy enough. However divisibility by 3 is not so simple - the rule is to add up all of the digits of the number and if they are a multiple of 3 then the original number is also.
Divisibility by 20: It is divisible by 10, and the tens digit is even.
so it has to end it a 0.
100
400
900
1600
2500
the tens digit has to be even because of the 20 but 0 is even
the sum of the digits has to be divisible by 9
900
that leaves 900 as the answer