Hairu shares his stickers part 10(Math Question)

Standard

Upper primary school mathematics question UPQ42

Hairu and Sarin shared some stickers. When Hairu gave 20 stickers to Sarin, both of they would have same amount of stickers. If Sarin gave 20 stickers to Hairu, Hairu would have 5 times as many stickers than Sarin. How many stickers did each of them have?

Solution:

When Hairu gave 20 stickers to Sarin, they had an equal amount of stickers. There was 40 stickers difference between them.

The math model,

 

When Sarin gave 20 stickers to Hairu, Sarin’s stickers reduced from the “White” portion to the “Green” portion. At the same time Hairu got 20 more stickers.

Since, Hairu had 5 times as many stickers than Sarin after received 20 more stickers,

4 times = 4 units = 80 stickers

Hairu had 4 units = 80 stickers

Sarin had 2 units = 40 stickers

Alternative solution:

By guess and check

Note:

1. Start the guess with stickers more than 20

2. Hairu has more stickers that Sarin 

Guess

    Check       Check

Sarin

Hairu

S + 20

H – 20

 

H + 20

S -20

Times

 

30

60

50

40

×

 

 

 

×

30

65

50

45

×

 

 

 

×

30

70

50

50

90

10

9

×

40

70

60

50

×

 

 

 

×

40

80

60

60

100

20

5

Hairu had 4 units = 80 stickers

Sarin had 2 units = 40 stickers

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