2 out of 5 times 3 out of 8 times 10 out of 9= Four by one twelfth by three fourths= Seven eighties by twenty-five twenty-four by three fourths= One quarter by eighteen fifths by twenty-five twelfth= 15 / 4 by 8 / 3 by 9 / 25= Two ninths by three Sevens by three eighties= Five out of two by twenty-seven out of ten by five out of twelve=

2 out of 5 times 3 out of 8 times 10 out of 9= Four by one twelfth by three fourths= Seven eighties by twenty-five twenty-four by three fourths= One quarter by eighteen fifths by twenty-five twelfth= 15 / 4 by 8 / 3 by 9 / 25= Two ninths by three Sevens by three eighties= Five out of two by twenty-seven out of ten by five out of twelve=

2 out of 5 times 3 out of 8 times 10 out of 9 = 1 / 6
4 times 1 / 12 times 3 / 4 = 1 / 4
7 / 18 times 24 / 25 times 3 / 14 = 2 / 25
1 / 4 by 18 / 5 by 25 / 12 = 15 / 8
15 / 4 by 8 / 3 by 9 / 25 = 18 / 5
2 / 9 by 3 / 7 by 3 / 8 = 1 / 28
5 / 2 times 27 / 10 times 5 / 12 = 45 / 16

2 times 3 times 4:1 plus 3 times 4 times 5:1. Plus 8 times 9 times 10:1

Original formula = 1 / 2 * (1 / 2 * 3-1 / 3 * 4 + 1 / 3 * 4-1 / 4 * 5 +. + 1 / 8 * 9-1 / 9 * 10)
=1/2*(1/6-1/90)
=1/2*(14/90)
=7/90

Simple calculation: 1 / 11 times 36 plus 9 / 11 times 29
fast

Da Chong Feng 00:
1/11×36+9/11×29
＝36/11+261/11
＝297/11
＝27
It's easy to do it step by step
Good luck and goodbye

(11-36th) plus (9-36th 11 times 5)

=11-1/36+9-55/36
=20-56/36
=20-14/9
=18+2-14/9
=18+4/9
=18 and 4 / 9