dtweah wrote:maihuna wrote:P Q and R are three typists who working simultaneously can type 216 pages in 4 hours. In one hour R can type as many pages more than Q as Q can type more than P. During a period of 5 hours, R can type as many pages as P can during 7 hours, How many pages each of them type per hour:
14, 17, 20
15, 17, 19
15, 18, 21
16, 18, 20
16, 19, 22
Choose C.
I actually love this problem. On the phase of it it looks intimidating but when you dig into it, it is not. Stick with principles:
Let R, P and Q be the job each do in 1 our respectively.
If they do 216 in 4 hours, find how many they do in 1 hour.
216/4=54.
So you know R +P+Q=54 --------(1)
In one hour R can type as many pages as Q as Q can type many pages more than P. This is Mathematese for
R-Q=Q-P
R= 2Q-P -----(2)
Comes another confusing joint: During a period of 5 hours, R can type as many pages as P can during 7 hours.
But we know P is number P can do in 1 hour. So 7P is what he will do in 7 hours.
Since R is the number R can do in 1, in 5 hour R will do 5R.
Then 5R=7P -----(3)
2Q-P+P+Q=54
Q=18
R=36-P
But P = 5R/7
So R= 21
54-39=15
Choose C.
