There were some children in a museum.
13 of the children lined up in 9 long rows and
15 of the children lined up in 5 short rows. The remaining children did not line up. There are 10 more children in each short row than each long row.
(a) What fraction of the children did not line up?
(b) How many children lined up?
|
Long rows |
Short rows |
Number |
9 |
5 |
Value |
1 u |
1 u + 10 |
Total value |
9 u |
5 u + 50 |
(a)
Fraction of children who did not line up
= 1 -
13 -
15 = 1 -
515 -
315= 1 -
815=
715(b)
515 of the children lined up in long rows.
9 u = 5 p --- (1)
315 of the children lined up in short rows.
5 u + 50 = 3 p --- (2)
(1)
x3
27 u = 15 p --- (3)
(2)
x5
25 u + 250 = 15 p --- (4)
(3) = (4)
27 u = 25 u + 250
27 u - 25 u = 250
2 u = 250
1 u = 250 ÷ 2 = 125
Number of children who lined up
= 9 u + 5 u + 50
= 14 u + 50
= 1750 + 50
= 1800
Answer(s): (a)
715; (b) 1800