Integer class 7 | R.S Aggaewal

For each positive integer n, let S_n =sum of all positive integers less than or equal on n. Then S_(51) equals

The positive integers p ,q and r are all primes if p^2 − q^2 = r , then possible value of r is 3 (b) 5 (c) 7 (d) 1

Class 7th ch 1 notes

If an integer a is greater 7, then |7-a|= (a) 7-a (b) a-7 (c) 7+a (d) -7-a

f:xto highest prime factor of x. A set of positive integers is called S. What can be said about these integers if (f)(S)=S?