Thank you for your help.
Q1)During a warehouse book sale, Sally spent 62.5% of her money on 24 books and 18 pens. She also spent 25% of her remaining money on 18 files. Each pen costs 8/9 as much as the price of one book. The file costs $7.80 less than a book. Find the total cost of one book and one pen.
Q2)There are 600 children in Team A and 30% of them are boys. There are 400 children in Team B and 60% of them are boys. After some children are transferred from Team B to Team A , 40% of the children in Team A and 60% of the children in Team B are boys. How many children are transferred from Team B to Team A?
total money = 32 units.
money spent on 24 books and 18 pens = 20 units
mony left = 12 units
money spent on 18 files = 3 units
Let's look at the 20 units...
1 pen cost 8/9 of 1 book
18 pens cost 16 books
20 units equal to 24 books + 16 books = 40 books
1 book = 0.5 unit.
Let's look at files...
18 files = 3 units
1 file = 1/6 units
compare files and books
work out the rest...
Originally posted by Tianzhu09:Thank you for your help.
Q1)During a warehouse book sale, Sally spent 62.5% of her money on 24 books and 18 pens. She also spent 25% of her remaining money on 18 files. Each pen costs 8/9 as much as the price of one book. The file costs $7.80 less than a book. Find the total cost of one book and one pen.
Q2)There are 600 children in Team A and 30% of them are boys. There are 400 children in Team B and 60% of them are boys. After some children are transferred from Team B to Team A , 40% of the children in Team A and 60% of the children in Team B are boys. How many children are transferred from Team B to Team A?
team A has 3/10 times 600 = 180 boys, 420 girls
team B has 6/10 times 400 = 240 boys, 160 girls
after transfer, team B still have same ratio of boys to girls. Hence, the number of boys and girls transferred maintain the same ratio, 3 boys to 2 girls.
after transfer, team A has 180 + 3 units of boys, 420 + 2 units of girls.
Since new ratio is 40% boys and 60% girls,
3 x team A boys = 2 times team A girls
540 +9 units = 840 + 4 units
5 units = 300
1 unit = 60
hence, total transferred = 5 times 60 = 200 children.