I think its refering to the 3side of the triangle each is 2400. So the 4 circles add up got to be 2400

Not sure if there is more than one answer. As suggested by Kim Soon Chin, divide by 100. A bit of trial and error. Notice that 3, 6 and 9 can divide by 3. 1, 4, 5, 7 , 8, 10 cannot be divided by 3. So 3 corners try 3, 6, 9 So one side would be 3+6+7+8 = 24 Another side would be 3+9+2+10=24 reject as there is no 2. 3+9+3+9=24 reject as 3 repeated. 3+9+4+8=24 reject as 8 already used. 3+9+5+7 =24 reject as 7 already used 3+9+6+6 =24 reject as 6 repeated. So 3 corners try 1, 3, 4 1+3+10+10=24 reject as 10 repeated So 3 corners try 8, 9, 10 9+10+1+4=24 Second line 8+10+3+3=24 reject as 3 repeated 8+10+2+4 reject bec no 2 8+10+1+5 reject bec q used twice. So 3 corners try 7, 8, 9 First line 8+9+3+4=24 Second line 7+9+4+4 reject bec 4 repeated 7+9+3+5 rejected as 3 used already. 7+9+2+6= 24 reject as no 2. 7+9+1+7=24 reject as 7 used twice. So first line 8+9+1+5 Second line 7+9+4+4=24 reject 7+9+3+5 reject as 5 repeated 7+9+1+6=24 reject as 1 repeated. Very tedious.

So 3 corners try 3, 6, 8 Already tried 3+6+7+8 So try 3+6+6+9 reject 3+6+5+10=24 Second line 3+9+6+6 reject 3+9+5+7 reject 3+9+4+8=24 Third line Left 1, 7 6+9+1+7=23 reject.

As mentioned, sum of 3 corners must be 1900

Arr ... i miss that part ....

Avoid putting extremely large or small numbers at corners as they will b used twice.

The combined width of 2 boxes is equal to the width of the cupboard ie. 0.9m or 90 cm. In Figure B, the height of the 4 boxes placed horizontally is equal to 180cm (=90/2 x 4). 2u + 42 = 180 + 10 2u = 190 - 42 = 148 1u = 74 Gap = 90 - 74 = 16 cm Height of cupboard = 3u + 42 = 3x74 + 42 = 264cm = 2.64m

because when we assume all are 20¢ coins, we are short of $107.90. Since every 50¢ coin has 30¢ more value than every 20¢ coin, we need $107.90/$0.30＝117 of 50¢ coins to compensate the lack of $107.90.

How to add all $1, $0.20 & $0.50 to get $133.90?

the $1 is given by the mum, total of 26 times. It is actuaclly the number of 20¢ and 50¢ that we need to find. Total number of 20¢ and 50¢ coins is give by number of days,182.

So that mean 26 X $1 = $26 + 364 X $0.20 = $72.80 + 117 X $0.50 = $58.50 ($157.30) and not $133.90

Micheal Lim, you missed a step when using the assuming method: Number of $1 = 26 Number of $0.50 = 117 To find the actual number of $0.20, you need to use 364 (which is the total of $0.50 and $0.20) and minus 117(which is the $0.50 you found) Number of $0.20 = 364-117= 247

Hi Stacey, thanks.

Not very sure and dont know how to build model...

Hi Stacey Tan, can u kindly explain the parts on 26-20mins and 20-12.5mins and it becomes 7.5m for B and 6m for C? Thanks

We are told that if B and C do it together, they will complete in 20 mins => the average speed is 20 mins. [from the table calculation] The 6 mins extra from B was actually to help C do what C would need to complete in 7.5 mins. So B only needs 6 mins to do what C can do in 7.5 mins. That gives us the ratio to work on.

Okie. I got it! Thanks

Brandon alone --> 5+21+6+4=36

My 2 cents

Thanks for your question ^^