Question 1

A farmer sold 23 of his herd of cows on the first day.

He sold another 81 cows on the second day.

He bought 40 cows on the third day.

He then had 55 cows on his ranch.

How many cows did the farmer have at first?

Question 2

Carson gave 30 marbles to his sister.

He gave another 16 marbles to his friend before he bought another 10 marbles.

He then had 15 marbles.

How many marbles did Carson have at first?

Question 3

Lin Chen had some books.

She lent half of them to Wilson.

She lent half of the remaining books to teacher Jenny.

She was then left with 15 books.

How big was Lin Chen’s collection of books at first?

Question 4

Lin Chen borrowed many books from libraries.

Half of the books were from Jurong East Library.

The remaining half were from Clementi Library.

The rest 4 books were from Boon Lay Library.

How many books did she borrow?

Question 5

12 sparrows were resting on 2 lamp posts.

2 sparrows flew from the first to the second lamp post.

3 sparrows flew from the second to the first lamp post.

The number of sparrows on the first and the second lamp posts became the same.

How many sparrows were there on each lamp post at first?

Question 6

16 sparrows were resting on two branches of a tree.

4 sparrows flew from the second branch to the first one.

6 sparrows flew from the first branch to the second one.

There were then 2 more sparrows on the first branch than the second one.

How many sparrows were on each branch at first?

Question 7

The 1st and 2nd shelves of a bookshelf contained 100 books altogether.

20 books were transferred from the 1st to the 2nd shelf.

35 books from the 2nd shelf were transferred back to the 1st one.

The two shelves now contained the same number of books.

How many books were on each shelf at first?

Question 8

Two groups of penguins consist of 300 penguins in all.

30 penguins move from the first group to the second one.

50 penguins move to the first group from the second one.

The number of penguins in group A doubles those in group B in the end.

How many penguins are there in each group at first?

Question 9

The East-Wing and the West-Wing of the Underwater World held 800 fish altogether.

120 fish swam over to the West-Wing from the East-Wing.

200 fish from the East-Wing swam over to the West-Wing.

The number of fish in the East-Wing became 3 times of those in the West-Wing.

How many fish were there in each wing of the Underwater World at first?