A simple arithmetic problem 2/2*4 * 2/4*6 + 2/6*8 + 2/8*10 + 2/10*12

A simple arithmetic problem 2/2*4 * 2/4*6 + 2/6*8 + 2/8*10 + 2/10*12

2/2*4 * 2/4*6 + 2/6*8 + 2/8*10 + 2/10*12=2/2(1/1*2+1/2*3+1/3*4+1/4*5+1/5*6)=1/1*2+1/2*3+1/3*4+1/4*5+1/5*6=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6=1-1/6=5/6

Ten simple mathematical problems
121 × 100 and 1 / 121 (simple calculation)
2.2.7 × 2.75 + 6.3 × 2.75 + 2 and 3 / 4 (simple calculation)
3.6 1 / 2 × 3.5 △ 1 2 / 3 (simple calculation)
4.3 1 / 8 △ 5 / 8-1 5 / 9 × 1 2 / 7 (simple calculation)
5.2000 △ 5-3 / 21 and 1 / 5 × 2000
Question 6. 3 / 8 × {3 and 1 / 2-2 and 1 / 2 △ 1 and 1 / 4} × 4 / 9
7.7/10×[3/4－(7/16-1/4)]

1.121*[100（1/121）]=121*100+1=12101
2. Extraction common factor = 2.75 (2.7 + 6.3 + 1) = 27.5
3. All are reduced to false scores = (13 / 2) * (7 / 2) * (3 / 5) = 273 / 20
4. Reduction = (25 / 8) * (8 / 5) - (14 / 9) * (9 / 7) = 5-2 = 3
5. Simplify, extract common factor = 2000 * (21 / 5) - (16 / 5) * 2000 = 2000 [(21 / 5) - (16 / 5)] = 2000
6. Simplification: (3 / 8) * [(7 / 2) - (5 / 2) * (4 / 5)] * (4 / 9) = (3 / 8) * [(7 / 2) - 2)] * (4 / 9) = (3 / 8) * (3 / 2) * (4 / 9) = 1 / 4
7.=(7/10)*[(3/4)-(3/16)]=(7/10)*(9/16)=63/160