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how many numbers are there between 11 and 60 and how many odd number how many perfect square number and prime number less than 20​

User Bluesman
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1 Answer

5 votes

Explanation:

did you write all requests without any typos or missing anything ?

I am going to answer what you wrote :

how many numbers between 11 and 60 ?

I assume we mean natural numbers, right ?

how many between 11 and 12 ? right, 0.

how many between 11 and 13 ? right, 1 (12).

and so on.

you notice a pattern ?

it is : high number - low number - 1

so, for 11 and 60 we get

60 - 11 - 1 = 48

there are 48 numbers between 11 and 60.

how many odd (uneven) numbers are between 11 and 60 ?

again, how many between 11 and 12 ? 0.

between 11 and 13 ? 0 (12 is not odd).

between 11 and 14 ? 1 (13).

between 11 and 15 ? 1 (13).

between 11 and 16 ? 2 (13, 15)

between 11 and 20 ? 4 (13, 15, 17, 19)

you see the pattern here ? it is

(high number - low number - 1)/2

so, for 11 and 60 we get

(60 - 11 - 1)/2 = 48/2 = 24

there are 24 odd numbers between 11 and 60.

if that division leads to a fraction, we need to round down to the next natural number.

e.g. between 11 and 59 there are

(59 - 11 - 1)/2 = 47/2 = 23.5 rounded down is 23. as between 11 and 59 there are only 23 odd numbers.

how many perfect square numbers between 11 and 60 ?

1² = 1 no.

2² = 4 no.

3² = 9 no.

4² = 16 yes.

5² = 25 yes.

6² = 36 yes.

7² = 49 yes.

8² = 64 no.

9² and any other larger numbers squared are too large.

so, we have 4 perfect square numbers between 11 and 60 (16, 25, 36, 49).

how many prime numbers less than 20 between 11 and 60 ?

next number after 11 : 12 (not a prime number, divisible by 2, 3, ...).

next number : 13 (yes, prime number).

next number : 14 (not a prime number, divisible by 2, 7).

next number : 15 (not a prime number, divisible by 3, 5).

next number : 16 (not a prime number, divisible by 2, 4, ...)

next number : 17 (yes, prime number).

next number : 18 (not a prime number, divisible by 2, 3 ...)

next number : 19 (yes, prime number)

done.

there are 3 prime numbers less than 20 between 11 and 60.

User RhinoWalrus
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