Saturday, May 2, 2009

Ratio Question Arthur Yusuf and Bill

Arthur, Yusuf and Bill had some stamps in the ratio 3:5:6. When Yusuf gave some stamps to Arthur and Bill gave 42 more than what Yusuf gave to Arthur, they all had the same number of stamps each. How many more stamps than Arthur did Yusuf have at first?

Before: A:Y:B = 3:5:6 (total 14 units)
After: A:Y:B = 1:1:1 (total 3 units)

Since the total number of stamps remain unchanged, use equivalent ratios for the total units. (LCM of 14 and 3 = 42)

so Before A:Y:B = 9:15:18 (total 42 units)
After A:Y:B =14:14:14 (total 42 units)

We see that A has gained 5 units, Y lost 1 unit and B lost 4 units

B lost 3 more units than Y (4-1).
From the question Bill gave 42 more stamps than Yusuf, so 1 unit = 14 stamps (42/3)

At the beginning, Arthur had 9 units and Yusuf 15 units (6 more units)
So Yusuf had 6x14=84 stamps more than Arthur

CM5 Unit4 Q3

No comments:

Post a Comment