algebraic approach?

[scoowhoop]

If a chef creates x pastries per hour, then how many minutes will it take to make 50 pastries?

a. x/50

b. 50/x

c. 60x/50

d. 50x/60

e. 50*60/x

This seems so simple to me but yet I still got it wrong. Can someone please show the algebraic approach? Thanks.

This question is from the Peterson's Prep Test

[DeepthiRajan]

Since the ques asks for amount of time in minutes we need to convert 1 hour to 60 mins and follow a simple relation

x pastries take 60 mins

50 pastries take z mins

Since more the time, more number of pastries can be created, hence direct relation

x:50 :: 60:z

therefore, z = (50*60)/x --->(E)

[rn4gmat]

The number of pastries per minute : x/60

The time for 50 pastries : 50/x/60 = 50*60/x hence the answer should be e.

Let says x = 60
so number of pastries per minute : 60/60 =1

so if we apply this rule for 50 pastries this would be : 50/60/60 = 50*60/60 = 50.

[scoowhoop]

Crystal clear now....I was in a rush and went with D.

Thanks!

[RJ43]

I like to think of these as Total = Rate * Time problems.

The rate is given first as X/hour and it gives us the total as 50 and wants the Time in minutes. So

50 = X * T

Convert the rate to minutes and get

50 = X/60 * T

Solve for T

(50) * (60) / X = T Answer E.

[tohellandback]

elimination:

let x is 50.

put it in the answer options..you should get 60. A,B and E are easily eliminated.

put x=25

put x in C and E.you should get 120.
answer is E