1.Alan has a stamp collection.60% of them are Japanese stamps and rest are Korean stamps.
she gave away 63 Korean stamps and 25% of the Japanese stamps.she then had 5/8 of her stamp collection left .how many stamps did Alan give away?

2.To keep herself fit Roselin climb up a flight of 30 step every day.if she runs up 5 steps and walks up 25 steps,she will take 99 seconds.if she runs 15 steps and walk 15 steps ,she will take 18 seconds less.how long will she take to run up all the 30 steps.if she maintains the same speed.

Question 2
If Roselin runs 5s and walks 25s she will take 99secs.
If she runs 15s and walks 10s she will take 18secs. less
therefore every 10s she runs she will save 18secs
if she runs all 30 s she will save 54secs.
She will take 45secs. to run all 30 steps

Alan has a stamp collection.60% of them are Japanese stamps and rest are Korean stamps.
He gave away 63 Korean stamps and 25% of the Japanese stamps. He then had 5/8 of her stamp collection left .how many stamps did Alan give away?

J : K
(begin) 60% : 40%
-25% : -63 stamps
(end) 45% : *17.5%

total stamps left: 5/8 of 100% = 62.5%
62.5% - 45%(J) = *17.5%

(40% - 17.5%) = 22.5% -> 63 stamps
Thus, 1% -> 2.8 stamps
Total % of stamps given away : 100% - 62.5% = 37.5%
37.5% -> 105 stamps (ans)

To keep herself fit, Roselin climbs up a flight of 30 steps every day. If she runs up 5 steps and walks up 25 steps, she will take 99 seconds. If she runs 15 steps and walk 15 steps , she will take 18 seconds less. How long will she take to run up all the 30 steps if she maintains the same speed?

5r + 25w = 99 (x3)
--> 15r + 75w = 297sec
15r + 15w = 81sec
60w = 216sec
1w = 3.6sec
1r = 1.8sec
30r = 54 sec

Hi, I just got to understand your method of working. However, you made a mistake in your second last sentence. You should have used 25s to calculate the time saved instead of 30s since she has already ran 5s.