Thursday, October 7, 2010

Whole Number PSLE 2010 P2 Q12

A group of girls shared some sweets among themselves. They tried taking 11 sweets each, but found that the last girl had only 6 sweets. When each girl took 8 sweets, there were 25 sweets left over. How many sweets were there altogether?



                                                            [     ]   -- 1 u
[    ][    ][    ][    ][    ][    ][    ][    ][    ][    ][6][5]
[    ][    ][    ][    ][    ][    ][    ][    ][       25   ]

3 u  -->  25  +  5  =  30

1 u  -->  30/3 = 10

11 u  -->  11 x 10  =  110

110  - 5  = 105  sweets

There are 105  sweets.


Alternative method
-------------------------
11 x (n - 1)  +  6  -->  8  x  n  +  25

3 n  -->  25  -  6  +  11  =  30

n  -->  30/3  =  10

8  x  10  +  25  =  105 sweets

There are  105  sweets.

3 comments:

  1. To solve this question,is this acceptable in PSLE:

    8[25+(11-6)/(11-8)]+25= 105

    ReplyDelete
  2. Zero mark. The workings are wrong. There is a missing bracket.

    ReplyDelete
  3. As appeared in PSLE 2010 exam:

    A group of girls shared some sweets among themselves. They tried taking 11 sweets each, but found that the last girl had only 6 sweets. When each girl took 8 sweets, there were 25 sweets left over. How many sweets were there altogether?

    ReplyDelete