can anyone help me to do these questions?

1.There are 30 pencils and 90 erasers in box A,there are 40 pencils and 20 erasers in box B. how many pencils and erasers must be moved altogether from box A to Box B so that 25% of the items in box A and 50 % of the items in Box B are pencils?

2.some workers arranged chairs in 14 short rows and 12 long rows.each long row had 18 chairs then each short row.60% of the chairs were arranged in long row while the rest of them were arranged in short row.how many chairs were there in all?

muthu wrote:
1.There are 30 pencils and 90 erasers in box A,there are 40 pencils and 20 erasers in box B. how many pencils and erasers must be moved altogether from box A to Box B so that 25% of the items in box A and 50 % of the items in Box B are pencils?
Box A
30 pencils - P (25%)
90 erasers - E (75%)

Box B
40 pencils + P (50%)
20 erasers + E (50%)

Box A
Pencils : Erasers
30-P : 90-E
25 : 75
1 : 3

3(30-P)=1(90-E)
90-3P=90-E
3P=E

Box B
Pencils : Erasers
40+P : 20+E
50 : 50
1 : 1

40+P=20+E
Since E=3P then
40+P=20+3P
2P=20
P=10
E=3x10=30

10 pencils and 30 erasers must be moved altogether from box A to Box B so that 25% of the items in box A and 50 % of the items in Box B are pencils.

muthu wrote:
2.some workers arranged chairs in 14 short rows and 12 long rows.each long row had 18 chairs then each short row.60% of the chairs were arranged in long row while the rest of them were arranged in short row.how many chairs were there in all?
Hi Muthu,
I believe that there are typo errors in your question 2. Below is the edited question:

Some workers arranged chairs in 14 short rows and 12 long rows.Each long row had 18 chairs more than each short row.60% of the chairs were arranged in long row while the rest of them were arranged in short row.How many chairs were there in all?

Assume the number of chairs in each short row be N.

Total number of chairs in 14 short rows = 14xN=14N
Total number of chairs in 12 long rows = 12x(N+18)=12N+216

14N-> 40%
12N+216-> 60%

10%->3.5N
60%-> 21N

12N+216=21N
9N=216
N=24

Total number of chairs in all = (14x24)+(12x24)+216 = 840

Hope this helps as well