Question

How many numbers less than or equal to 1000 a) are divisible by 3 or 5 ... b) are divisible by 3 and 5 c) are not divisible by 3 nor by 5. pls help me i got 5 more minutes to write it for a good mark

Answer 1

Let x, are divisible by another number, Let y, you just have to divide x by y and the quotient you get is your answer.

So, 1000/7 gives a quotient = 142

And 1000/11 gives a quotient = 98

Thus, there are 142 and 98 numbers less than 1000 which are divisible by 7 and 11 respectively.

And if you want to know the count of numbers which are divisible by both 7 and 11 and less than 1000. Just take the L.C.M. of 7 and 11 i.e. 77 and divide 1000 by 77 giving quotient = 12 which means there are only 12 numbers less than 1000 which are divisible by both 7 and 11.

Answer 2

Answer:

a answer-. divisible by 3 or 5 is = 467

b answer -.

divisible by 3 and 5 is =66

c answer - are not divisible by 3 or 5 is = 533