Try solving this Math question ...

[ahmadka]

Hi guys ... I've come across a math question which I want to get everyone's opinion on:

"Caleb spends $72.50 on 50 hamburgers for the matching band. If single burgers cost $1.00 each and double burgers cost $1.50 each, how many double burgers did he buy ?"

The answer for the above question is 45, however I don't see how that is calculated.

Can someone explain ?

[alanifamily]

You have two variables and two equations. Let's say X is regular burgers and Y is double,

 

One equation is for the total cost of the burgers:

1*X+1.5*Y=72.5

 

Another is for the number of burgers:

X+Y=50

 

Two equations, two unknowns. Subtract the 2nd equation from the first one. You get .5*Y=22.5. Solve for Y. Y=45.

[ahmadka]

So you're counting 'double burger' as a single burger too ?

 

Doesn't a 'double burger' mean two burgers. I mean, buy one burger for $1, buy 2 for $1.50, and save 50 cents ?

 

The way I see, Caleb can just as well buy 50 single burgers and still the total would be $50, not $72.50. If he buys double burgers too (two burgers), the total cost would be less than $50 ..

 

The wording is ambiguous probably, or is it just me ?

[kimchijajonshim]

So you're counting 'double burger' as a single burger too ?

 

Doesn't a 'double burger' mean two burgers. I mean, buy one burger for $1, buy 2 for $1.50, and save 50 cents ?

 

The way I see, Caleb can just as well buy 50 single burgers and still the total would be $50, not $72.50. If he buys double burgers too (two burgers), the total cost would be less than $50 ..

 

The wording is ambiguous probably, or is it just me ?

Hahahaha, this is a language/cultural barrier thing. A double burger is not two separate burgers. A double burger is a single burger with twice as much meat.

 

x+y = 50

x + 1.5y = 72.50

 

Solve for x. Simple as that.

[alanifamily]

Hahahaha, this is a language/cultural barrier thing. A double burger is not two separate burgers. A double burger is a single burger with twice as much meat.

 

x+y = 50

x + 1.5y = 72.50

 

Solve for x. Simple as that.

 

Solve for Y. In your equation, X is the single burger

[jujubea]

A double burger means one burger that has two patties of meat in it.

English language is crazy confusing, don't sweat it.

[Brent@GreenlightGRE]

Caleb spends $72.50 on 50 hamburgers for the marching band. If single burgers cost $1.00 each and double burgers cost $1.50 each, how many double burgers did he buy ?

We can also solve this question using 1 VARIABLE. 

 

Let x = the NUMBER of double burgers purchased 

Since a total of 50 burgers were purchased, we know that...

50 - x = the NUMBER of single burgers purchased 

 

single burgers cost $1.00 each and double burgers cost $1.50 each

So ($1.5)(x) = the total COST of the double burgers 

And ($1)(50 - x) = the total COST of the single burgers

 

The total cost was $72.50

So, (1.5)(x) + (1)(50 - x)  = 72.50

Expand: 1.5x + 50 - x = 72.50

Simplify: 0.5x + 50 =  72.50

Subtract 50 from both sides:  0.5x =  22.50

Divide both sides by 0.5 to get: x = 45

 

So, 45 double burgers were purchased.

 

Cheers,

Brent