They are also called Gaps and Differences Concept questions.
Sometimes, they are called Double If Concept questions because they always involve 2 possible scenarios.
a) How many bags did he buy?
b) How many marbles did he buy?
ES2:
Bala wanted to buy 10 wallets, but he found himself short of $14. In the end, he decided to buy 7 wallets and had $5.20 left.
ES1:
Ali bought a number of marbles and bags. He packed 10 marbles into each bag and found that he had 11 marbles left over. If he packed 12 marbles into each bag, he would need another 7 more marbles.a) How many bags did he buy?
b) How many marbles did he buy?
Bala wanted to buy 10 wallets, but he found himself short of $14. In the end, he decided to buy 7 wallets and had $5.20 left.
(a) How much did Bala pay for each wallet?
(b) How much money did Bala have with him when he went to buy the wallets?
ES3:
Mrs Tan gave some crayons to her pupils. She wanted to give each pupils 15 crayons, but found herself short of 12 crayons. Instead, she gave 12 crayons and had 42 crayons left.
Mrs Tan gave some crayons to her pupils. She wanted to give each pupils 15 crayons, but found herself short of 12 crayons. Instead, she gave 12 crayons and had 42 crayons left.
(a) How many pupils did she have?
(b) How many crayons did Mrs Tan have at first?
A group of boys shared some stamps among themselves. They tried taking 20 stamps each, but found that the last boy had only 11 stamps. When each boy took 18 stamps, there were 7 stamps left over.
a) How many boys were there in the group?
b) How many stamps were being shared by the boys?
A group of boys shared some stamps among themselves. They tried taking 20 stamps each, but found that the last boy had only 11 stamps. When each boy took 18 stamps, there were 7 stamps left over.
a) How many boys were there in the group?
b) How many stamps were being shared by the boys?
ES5:
There are some girls in a class.If I give each girl 8 stickers, I will have 24 stickers left.
If I give each girl 11 stickers, I will be short of 6 stickers.
(a) How many stickers do I have?
(b) How many girls are there in the class?
You might be interested in the model method of solving Excess & Shortage questions which is explained in the following video:
Here's another video also on Excess & Shortage:
