Marion made 520 biscuits and tarts. After she gave 0.1 of the biscuits and 0.6 of the tarts to her pupils, she was left with an equal number of biscuits and tarts. How many biscuits had she left?
| |
Biscuits |
Tarts |
Before
|
10x2 =
20 u |
5x9 =
45 u |
Change
|
- 1x2 =
- 2 u |
- 3x9 =
- 27 u |
After
|
9x2 =
18 u |
2x9 =
18 u |
Comparing biscuits and
tarts in the end |
1x18 =
18 u |
1x18 =
18 u |
0.1 =
110 0.6 =
610 =
35 The number of biscuits and tarts is the same in the end. Make the number of biscuits and tarts in the end the same. LCM of 9 and 2 and 1 is 18.
Total number of biscuits and tarts at first
= 20 u + 45 u
= 65 u
65 u = 520
1 u = 520 ÷ 65 = 8
Number of biscuits that Marion had left
= 18 u
= 18 x 8
= 144
Answer(s): 144
