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todd2000

macrumors 68000
Original poster
Nov 14, 2005
1,624
11
Danville, VA
If a block weighs eight kilograms plus half a block, what is the weight of a block and a half?

I'll chime in after a few answers...

Explain your answer please...
 

spork183

macrumors 6502a
Jul 30, 2006
878
0
If a block weighs eight kilograms plus half a block, what is the weight of a block and a half?

I'll chime in after a few answers...

Explain your answer please...

if it weighs 8kilo + 1/2 a block (4kilos) = 12 kilos for 1 block. so a block and a half would weigh 18kilos.

Now, if the word play is to lock in the weight of a block at 8 kilos, then your 1.5 blocks would be 12kilos.

I'm pretty tired, so if I amusingly punted this one, enlighten (ridicule :D ) me.
 

angelneo

macrumors 68000
Jun 13, 2004
1,541
0
afk
1 block weighs 8kg + half a block
half a block weighs 8kg
1 block weighs 16kg
hence, 1 and a half blocks weighs 16+16/2 = 24kg
 

todd2000

macrumors 68000
Original poster
Nov 14, 2005
1,624
11
Danville, VA
1 block weighs 8kg + half a block
half a block weighs 8kg
1 block weighs 16kg
hence, 1 and a half blocks weighs 16+16/2 = 24kg

It says the answer is 24, but I'm still stuck at 18...

If 1 block weighs 8kg + half a block, then how can 1/2 a block weight 8kg?

It should be 8kg+4kg = 12kg

1/2 of 12kg = 6kg + 12kg(one block) = 18kg
 

swiftaw

macrumors 603
Jan 31, 2005
6,328
25
Omaha, NE, USA
ok, suppose a block weighs x kg

Then x = 8 + 0.5 x meaning that 0.5 x = 8 meaning x = 16


The question says, how much does 1.5 blocks weigh,

well 1.5*x = 1.5 * 16 = 24
 

spork183

macrumors 6502a
Jul 30, 2006
878
0
ok, suppose a block weighs x kg

Then x = 8 + 0.5 x meaning that 0.5 x = 8 meaning x = 16


The question says, how much does 1.5 blocks weigh,

well 1.5*x = 1.5 * 16 = 24

ah, quite simple if you use your head. For those like me who locked into the 8kg as a finite weight, think of it like this:
A block weighs 1/2 a block + 8kg. That makes it easier for me to solve. Your mileage may vary...
 

leftywamumonkey

macrumors 6502a
Jun 23, 2010
909
3
California
1 block = 1/2 block + 8kg
subtract 1/2 block from both sides
1/2 block = 8kg
multiply both sides by 2
1 block = 16kg

You need to find the weight of 1-1/2 block.

1block * (1.5) = 16kg * (1.5)
1.5 blocks = 24kg
 

angelneo

macrumors 68000
Jun 13, 2004
1,541
0
afk
It says the answer is 24, but I'm still stuck at 18...

If 1 block weighs 8kg + half a block, then how can 1/2 a block weight 8kg?

It should be 8kg+4kg = 12kg

1/2 of 12kg = 6kg + 12kg(one block) = 18kg
This might be easier for you to visualize,
Code:
1 block = 1/2 block + 1/2 block
1 block =    8kg    + 1/2 block

Hence,
1/2 block = 8kg,
and 1 block = 8x2 = 16 kg
 
Last edited:

Carlanga

macrumors 604
Nov 5, 2009
7,132
1,409
Should be Y=1.5X so Y=1.5 * total weight(16) = 24. Reminds me of the SAT's
The key to killing the math part is making every problem like this into a simple formula to solve. Don't get stuck in the semantics of the questions or you will get them wrong.
 

peeaanuut

macrumors 65816
Sep 10, 2007
1,048
1
Southern California
the word play is to get you to lock into the number eight. So you hear 8+half and you think 12, then you add half that and get 18. The idea is to get you to actually use formulas and do the math instead of just going off the only visible number which is 8. The actual math, as the formulas have shown equals out to 24.
 

samiwas

macrumors 68000
Aug 26, 2006
1,598
3,579
Atlanta, GA
1 block = 1/2 block + 8kg
subtract 1/2 block from both sides
1/2 block = 8kg
multiply both sides by 2
1 block = 16kg

You need to find the weight of 1-1/2 block.

1block * (1.5) = 16kg * (1.5)
1.5 blocks = 24kg

Ah ha! This finally made me understand what on earth people here were saying.
 
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