1)Mrs Chan had some beads. 38% of the beads were red and the rest were yellow. After she had bought some more red beads,the percentage of red beads increased to 84% of the total number of beads. How many red beads did she buy if she had 496 yellow beads?
2)Yusof had a total of 560 local and foreign stamps. After giving away 80% of the local stamps and 50% of the foreign stamps,he had 172 stmaps left.
a)How many local stamps did he have at first?
b)How many foreign stamps did he give away?
thank you.
Originally posted by Ashleeann hannah:1)Mrs Chan had some beads. 38% of the beads were red and the rest were yellow. After she had bought some more red beads,the percentage of red beads increased to 84% of the total number of beads. How many red beads did she buy if she had 496 yellow beads?
2)Yusof had a total of 560 local and foreign stamps. After giving away 80% of the local stamps and 50% of the foreign stamps,he had 172 stmaps left.
a)How many local stamps did he have at first?
b)How many foreign stamps did he give away?
thank you.
1.
Original amount of red beads
= [ 496 / 62% ] X 38% = 304 red beads
Current amount of red beads
= [ 496 / 16% ] X 84% = 2604 red beads
Amount of red beads she bought
= 2604 - 304 = 2300 red beads
2.
20% of local stamps + 50% of foreign stamps = 172 stamps
40% of local stamps + 100% of foreign stamps = 172 X 2 = 344 stamps
100% of local stamps + 100% of foreign stamps = 560 stamps
=> 60% of local stamps = 560 - 344 = 216 stamps
(a)
Amount of local stamps he has at first
= [ 216 / 60% ] X 100% = 360 stamps
(b)
100% of foreign stamps = 560 - 360 = 200 stamps
Amount of foreign stamps given away
= 50% of all foreign stamps
= 50% X 200 = 100 stamps