Question

50x , ,
The number of 2-digit numbers, greater than 10, divisible by 2 and 5 but not by 4 or 25 is :
a)2
b)3
c)5
d)12​

Answer 1

Step-by-step explanation:

How many two-digit numbers that are greater than 10 are divisible by 2 and 5, but not by 4 or 25?

Stop giving away your data. Sell it.

Mamta Kumari

Answered 2 years ago

As they have to be divisible by 2 and 5 simultaneously we have to check the multiples of its LCM(least common multiple).

The LCM of 2 and 5 is 10.

So, the numbers have to be divisible by 10.

The numbers must be 10,20,30,40,50,60,70,80 and 90 but not 100 as it is three digit number.

But 20,40,60 and 80 are divisible by 4.

So, we are left with 10,30,50,70 and 90

According to the above condition the numbers must be greater than 10

So 10 is also excluded

We are left with

30,50,70 and 90

50 is divisible by 25

So, the left numbers are 30,70 and 90

And these three numbers are the two-digit numbers that are greater than 10 are divisible by 2 and 5, but not by 4 or 25.

Hope that helps.

Answer 2

Answer:

answer to This question is d)12