Question

Aratati ca 3supra 4mai mic decat 1supra 3+1supra 4+1supra 5+1supra 6+1supra 7+1supra 8mai mic decat 2

Answer 1

3/4< 1/3+1/4+1/5+1/ 6+1/7+1/8<2

1/3>1/8
1/4>1/8
1/5>1/8
1/6>1/8
1/7>1/8

1/3+1/4+1/5+1/ 6+1/7+1/8>6×1/8
1/3+1/4+1/5+1/ 6+1/7+1/8>3/4

1/3>1/4
1/3>1/5
1/3>1/6
1/3>1/7
1/3>1/8

6×1/3>1/3+1/4+1/5+1/ 6+1/7+1/8
2>1/3+1/4+1/5+1/ 6+1/7+1/8

rezulta
3/4< 1/3+1/4+1/5+1/ 6+1/7+1/8<2