Find Tuition/Enrichment Centres

AskQ logo

STUCK ON HOMEWORK?

ASK FOR HELP FROM OUR KIASUPARENTS.COM COMMUNITY!

Question

Answer

                                       Standing Broad Jump                Shuttle Run

Queuing At first                         7u                                           4u

18 from SBJ to SR                  -18                                           +18

Then the queues are equal, this implies

7u-18 = 4u+18

3u = 36

u =12

Hence queuing at SBJ  was 7u = 84 and queuing at SR was 4u = 48

At the end, both stations have  (84+48) = 132 pupils with each 66 pupils.

0 Replies 1 Like

 

Thinking:
Ratio is Jump:Run = 7:4. So we can use 7u:4u, a total of 11u.
After some movement they become equal, i.e. divisible by 2.
But 11 is not divisible by 2, so let's scale up by 2 instead.
We use Jump:Run = 14u:8u with a total of 22u (so 22u/2 = 11u).

Working:
            JUMP      RUN
BEFORE       14u       8u    (total of 22u students)
AFTER        11u      11u    (3u students moved)

So 3u = 18 and u = 6.

Thus at the start, there are 14 x 6 = 84 students in standing
board jump queue and 8 x 6 = 48 students in shuttle run queue.
At the end, there are 66 students in both queues.

Checking:
            JUMP      RUN
BEFORE       84        48 
AFTER     66=84-18  66=48+18 (18 students moved)

 

1 Reply 1 Like
Regarding the working you cancelled out, it can also be made to work:

             JUMP      RUN
BEFORE         7u       4u
AFTER       7u-18    4u+18

They are equal at the end, so 7u-18=4u+18 => 3u=36 => u=12.

It gives the same answer:

             JUMP        RUN
BEFORE    7x12=84    4x12=48
AFTER    84-18=66   48+18=66
0 Replies 1 Like
Find Tuition/Enrichment Centres