One out of two plus one out of six plus one out of twelve plus one out of twenty plus one out of thirty

1/2+1/6+1/12+1/20+1/30
=1/2+(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)
=1/2-1/6
=2/6
=1/3

RELATED INFORMATIONS

1. Two percent plus one sixth plus one twelfth plus one twentieth What's one in 110?
2. (): 24 = 3 / 8-12 divided by () = 30 ()
3. (): 24 = 3 / 8 = 12 divided by () = () 24 / 8
4. 8 / 3 = 30 = 24 / 3 = 4 / 3
5. Starting from 2, continuous even numbers are added, and the sum is as follows: 2 + 2 = 2 × 22 + 4 = 6 = 2 × 32 + 4 + 6 = 12 = 3 × 42 + 4 + 6 + 8 = 20 = 4 × 5 (1) What is the sum of N consecutive even numbers from 2? (2) Take n = 6 to verify whether the conclusion of (1) is correct
6. 2＝2＝1×2 2+4＝6＝2×3 2+4+6＝12=4×5 2+4+6+8=20=4×5 . 1. We can guess what is the sum of continuous even numbers from 2 to n (n is a natural number)? 2. When n = 10, what is the sum of continuous even numbers from 2 to the tenth?
7. -9+12÷(-6)-(-4)×(-4)÷(-8)
8. 3 / 4 = 6 / 8 = 9 / 12 = several
9. Find the rule and fill in the appropriate number in the brackets. (1) 45, 25, 15______ ，120，______ ，______ ．（2）12，34，98，2716，______ ，______ ．
10. Fill in the brackets with the appropriate number 4 / 1 9 / 1 16 / 1 () (). 2 / 1 6 / 1 12 / 1 20 / 1 30 / 1 () ()
11. How much is half plus five sixths plus eleven twelfth plus nineteen twentieth? It must be a simple calculation and try not to divide
12. 12+56+1112+1920+2930+… +97019702+98999900．
13. 12+56+1112+1920+… +98999900=______ ．
14. One half plus five sixths plus eleven twelfth plus nineteen twenties plus twenty-nine thirties. To 9899 9900 It's the method, not the calculation
15. 12+56+1112+1920+2930+… +97019702+98999900．
16. 11 / 20-19 / 30 + 29 / 42-41 / 56 + 55 / 72-71 / 90 + 89 / 110-109 / 132, there should be a process
17. 1/2+5/6+11/12+19/20+ ---- +89/90+109/110
18. 3 / 13, 4 / 19, 8 / 23, 12 / 35, 24 / 59
19. 18 / 5 + 10 / 7 + 18 / 13 + 10 / 1 is equal to?
20. 1-18 / 1 is equal to?