Maths Teaser Adults can't do.

This is a sum for primary school children which millions of Adults couldn't get right. Can you?

 

You have 3 parcels

Parcels A and B together weigh the same as parcel C

The three parcels weigh 800gms altogether

Parcel A weighs 250gms

How much does parcel C weigh?

 

................................

400gms......................

so C is half the weight of the total of 800 = 400

why do we need the weight of A? or am I missing something?

 

This si the sort of problem displayed at my lad's secondary school, so i don't know why they say its for primary school. Primary school for Oxbridge potentials perhaps? Might have been more sensionalist if they said it was for mums & baby's classes

400gms......................

That can't be right, can it? Because I would have said that as well, and I'm rubbish at maths. And if millions of adults can't get it right, why would we two be any different?

 

No, it must be more complicated than that.

A + B = C and A = 250 so...

(1) B - C = -250

 

A + B + C = 800 and A = 250 so...

(2) B + C = 550

 

(2) - (1)

B + C = 550

B - C = -250 -

2C = 800

C = 400

B = 150

 

jb

A+B+C=800

A+B=C

 

so C+C=800

C=400

 

Why do we need to know how much A weighs?

A+B+C=800

A+B=C

 

so C+C=800

C=400

 

Why do we need to know how much A weighs?

 

So that you can waste your doing doing it the long way like I did. D'oh.

 

jb

A+B+C=800

A+B=C

 

so C+C=800

C=400

 

Why do we need to know how much A weighs?

 

You don't in my day you wouldn't have it would have been.....

 

You have 3 parcels

Parcels A and B together weigh the same as parcel C

The three parcels weigh 800gms altogether

 

How much does parcel C weigh?

 

 

even then we would have p'd ourselves at how easy that was:hihi:

A+B+C=800

A+B=C

 

so C+C=800

C=400

 

Why do we need to know how much A weighs?

 

So that you can waste your doing doing it the long way like I did. D'oh.

 

jb

Indeed. Or maybe the problem with these so-called "elementary maths problems that adults can't do" is that the question is badly written that it confuses people?

Indeed. Or maybe the problem with these so-called "elementary maths problems that adults can't do" is that the question is badly written that it confuses people?

 

I agree, the weight of parcel A clouded things a little for me. It's a meaningless fact in the equation, but I started to wonder if parcels A and B are the same size and weight.

Is this maths or English comprehension?

Is this maths or English comprehension?

 

Both.

 

Rarely in life do mathematical problems present themselves in algebraic notation.