Question

1. If 25*215 is divisible by 3, then * can take the value:
(a)
(b) 3
(c) 4
2. Seive of Eratosthenes is a method to find:
(a) perfect numbers (b) prime numbers (c) twin primes
(d) 5
(d) co-primes​

Answer 1

Answer:

2) prime number... here is the answer of question number 1

Answer 2

Answer:

(b) 3

Step-by-step explanation:

To find :

25*215 is divisible by 3

Given :

2 5 x 2 1 5

Where x is the missing number that divisible by 3 when the x number is placed .

from the options if 3 is placed on behalf of *, then the number is 253215 and the sum is 2+5+3+2+1+5 = 18,then 18 is divisible by 3,so .....option b is correct

if we placed 4 on behalf of 3,the 254215 and the sum is 2+5+4+2+1+5=19 and 19 is not divisible by 3.....

so our answer is (b) 4

2.prime numbers

The Sieve of Eratosthenes is a strategy for tracking down all primes up to (and conceivably including) a given normal . n . This strategy functions admirably when is moderately little, permitting us to decide if any normal number not exactly or equivalent to is prime or composite.

Strainer of Eratosthenes is a strategy to track down the indivisible numbers and composite numbers among the gathering of numbers.

The project code is #SPJ3