PSLE A box contained green and yellow beads. At first, the number of green beads was
14 the number of yellow beads. After
23 of the green beads and
59 of the yellow beads were used, 209 beads were left.
- What fraction of the beads were left? Leave your answer in the simplest form.
- How many beads were used?
|
Green |
Yellow |
Comparing green beads and yellow beads at first |
1x9 = 9 u |
4x9 = 36 u
|
Before
|
3x3 = 9 u |
9x4 = 36 u |
Change
|
- 2x3 = - 6 u |
- 5x4 = - 20 u |
After
|
1x3 = 3 u |
4x4 = 16 u |
(a)
The number of yellow beads at first is repeated. Make the number of yellow beads at first the same.
LCM of 4 and 9 is 36.
The number of green beads at first is repeated.
Since the number of green beads at first is 9 u, we make the total number of green beads at first the same by multiplying 3 by 3 to become 9 u too.
Fraction of the beads left
=
3 + 169 + 36 =
1945 (b)
Number of beads left
= 3 u + 16 u
= 19 u
19 u = 209
1 u = 209 ÷ 19 = 11
Number of beads used
= 6 u + 20 u
= 26 u
= 26 x 11
= 286
Answer(s): (a)
1945; (b) 286