ruiruima

3 Questions
0 Answers

+1

28

1

+17

Number theory

How many positive integers are not less than the sum of their divisors?

ruiruima Jan 14, 2024

+2

30

1

+17

Ordered pairs of primes

How many ordered pairs of primes (a,b) satisfy a+b=22?

ruiruima Jan 13, 2024

+2

29

1

+17

Arithmetic sequence

The 80th term of an arithmetic sequence is twice the 30th term. If the first term of the sequence is 7, what is the 40th term?

ElectricPavlov ●

ruiruima Jan 12, 2024