Question

What is the value of the whole number N,if:N=1/2of2/3of3/4of4/5of100?

Answer 1

remember
(a/b) times (c/d)=(ac)/(bd) also
(ab)/c=(a/c)(b/c)
and
'of' means multiply


`( (1)/(2) )( (2)/(3) )( (3)/(4) )( (4)/(5) )( (100)/(1) )`=

`(1*2*3*4*100)/(1*2*3*4*5)`=

`( (2*3*4)/(2*3*4) )( (100)/(5) )`=

`(1)( (100)/(5) )`=

`(100)/(5)`=

`( (5)/(5) )( (20)/(1) )`=

`(1)( (20)/(1) )`=
20

answer is 20
or you can use bcalle's way and just cross multiply them

Answer 2

100/5 is 20/fifth so 4/5 of 100 is 80
80/4 is 20/quarter so 3/4 of 80 is 60
60/3 is 20/third so 2/3 of 60 is 40
40/2 is 20
the answer is N=20