Question

Amit can write 5 pages a day.Bella can erase 2 pages a day.How many days will they take to write 60 page record book if they work on alternate days?(amit works on the first day) time and work aptitude

Answer 1

I think this is write answer

Answer 2

Answer:

38.5

Step-by-step explanation:

Amit can write 5 pages per day, bell can erase 2 pages

so they are working on alternate answer.

Amit will start first.

so lets start..

1st day -> 5 books (Amit 5 pages)

2nd day-> 3 books (Bella erasing 2 pages)

3rd day ->8 books

4th day -> 6 books

5th day -> 11 books ….. so on up to let us say 59.

taking the count of alternate days, i.e. 1st day ,3rd day, 5th,7th like that.

so writing and erasing require "2 days"

Arithmetic progression : 5 , 8, 11, ….59

here a= 5,  d=3

an=a+(n-1)d

59=5+(n-1)3

59-5=(n-1)3

54/3=n-1

18=n-1

n=19

2n = 2*19 =38 (because writing and reading involves 2 days)

so for writing 59 books they require 38 days, on the very next day Amit will write 5 books , so it will be more than 60

Therefore the answer is *38.5*