bakery

[mberkowitz]

at a certain bakery, each roll costs r cents and each doughnut costs d cents. if Alfredo bought rolls and doughnuts at the bakery, how many cents did he pay for each roll?
1) Alfredo paid $5 for 8 rolls and 6 doughnuts.
2) Alfredo would have paid $10 if he had bought 16 rolls and 12 doughnuts.

Clearly if you can find 2 ways to buy 8 rolls and 6 doughnuts with $5, both the answer will be E.

My first reaction was to equate $5 to 500 cents, and say 8x +6y = 500, to solve for x and y. i then broke 500 down to its primes, thinking that x and y would be found using those primes.

can someone shed light on the best way to find these values for x and y?

oa is e

[raju232007]

cost of each roll=r cents
cost of each doughnut=d cents

statement 1:

8r+6d=500

We have only one equation and 2 unknowns

Insufficient

statement 2:

16r+12d=1000
8r+6d=500( dividing by 2 throughout)

This is nothing but the same equation in statement 1..

Insufficient

Combining both the statements we have a single equation 8r+6d=500
and 2 unknowns...Hence the value of r cannot be determined

The ans is clearly E...Let me know if you have any doubts

[mberkowitz]

appreciate the help, i originally thought that the ans is E bc there are various prices at which this is possible, but now understand your reasoning. who knows i'll bet there are prices for which this works.

if this was a ps problem, and they gave you statement 1 and asked you to find possible value for the price, how would you come up with an answer? or is this not doable?

tks

[mberkowitz]

appreciate the help, i originally thought that the ans is E bc there are various prices at which this is possible, but now understand your reasoning. who knows i'll bet there are prices for which this works.

if this was a ps problem, and they gave you statement 1 and asked you to find possible value for the price, how would you come up with an answer? or is this not doable?

tks

[nitya34]

classic trap Q
thanks

[mals24]

@mberkowitz

If this was a PS question with st1 and no additional information given then this question could not be solved because you have 2 unknown variables and only 1 equation. You need more information or another equation with which you can determine atleast one of the variables.

[vishubn]

Its straight forward

A) we know how many rols and doughnuts he bought ! 5$ for 8 and 6 !!
Insuff
B) preety msuh the same ! double the quaunt ! its same
Insuff

E is the OA

vishu