Simple calculation: (1-1 / 50) × (1-1 / 49) (1-1 / 3) × (1-1 / 2)

Simple calculation: (1-1 / 50) × (1-1 / 49) (1-1 / 3) × (1-1 / 2)

Simple calculation:
(1-1 / 50) × (1-1 / 49) (1-1 / 3) × (1-1 / 2)
=（-49/50）×（-48/49）×…… ×（-2/3）×（-1/2）
=-1/50

1 × 2 × 1 / 3 + 2 × 3 × 1 / 4 +How about 48 × 49 × 50

1 × 2 × 1 / 3 + 2 × 3 × 1 / 4 +48 × 49 × 50 / 1 = 1 / 2x [1 / (1x2) - 1 / (2x3) + 1 / (2x3) - 1 / (3x4) + +1/(48x49)-1/(49x50)]=1/2x[1/(1x2)-1/(49x50)]=1/2x[1/2-1/2450]=1/2x612/1225=306/1225

Calculation: 1 + 2 / 1 + 1 + 2 + 3 / 1 + 1 + 2 + 4 / 1 +... + 1 + 2 + 3 +... + 49 + 50 / 1

1+2+3+4+.+n=n(n+1)/2
∴1/(1+2+3+..+n)=2/n(n+1)=2[1/n-1/(n+1)]
1 + 2 of 1 + 1 + 2 + 3 of 1 + 1 + 2 + 4 of 1 +... + 1 + 2 + 3 +... + 49 + 50 of 1
=2（1/2-1/3+1/3-1/4+...+1/50-1/51)
=2×(1/2-1/51)
=2×49/102
=49/51
This is my conclusion after meditation,
If not, please ask, I will try my best to help you solve it~
If you are not satisfied, please understand~

Calculation: 2 times 1 / 3 plus 3 times 1 / 4 plus 49 times 1 / 50

1/(2*3)+1/(3*4)+...+1/(49*50)
=1/2-1/3+1/3-1/4+...+1/49-1/50
=1/2-1/50
=12/25

If one third of the number a is equal to three fifths of the number B, then how much is a better than B?

∵ 1 / 3A = 3 / 5B
A: B = 3 / 5:1 / 3 = 9:5

What's the result of dividing two fifths by five fifths and subtracting three fourths?

Change the product of "two fifths divided by five Sevens" into quotient, or change the division of "two fifths divided by five Sevens" into multiplication, because there is a problem with this topic

One sixth X: three quarters = 7: one and two fifths, four and two fifths: one and two Sevens = one and one third: (4-x)
15：90=（X+15）：150
Two and a fifth: 11 = x: one and a sixth

15：90=（X+15）：150
90（X+15）=15*150
X=10
Two and a fifth: 11 = x: one and a sixth
11X=11/5 * 11/6
X=11/30

1 / 2: 0.2 = 1 / 4: x 4 / 5: 2 / 15 = x: 9 (2-x): 5 = 3 / 20: x = 25%: 5 / 4
Solution ratio

One half: 0.2 = one fourth: x x = 1 / 4x0.2 △ 1 / 2x = 0.1, four fifths: two fifths = x: 9x = 4 / 5x9 △ 2 / 15x = 36 / 5x15 / 2x = 54 (2-x): 5 = three twentieth, 2-x = 3 / 20x5x = 2-3 / 4x = 5 / 4, one third: x = 25%: five fourths, x = 1 / 3x5 / 4 △ 25% x = 5 / 12x4x = 5 / 3

If two fifths of x equals one half of Y, then Y: x = ()

y：x
=2/5：1/2
=4：5
Do not understand can ask, help please adopt, thank you!

1 / 2 + 3 / 4 2 / 12 - 1 / 4 3 / 6 + 2 / 15 + 7 / 8 + 3 / 10

1.1/2+3/4=2/4+3/4=5/4
2.11/12-1/4=11/12-3/12=8/12=2/3
3.5/6+2/15=25/30+4/30=29/30
4.7/8+3/10=35/40+12/40=47/40