class 9 home

Page 62

5a)

Monthly charge of the electricity =945

Let x units of electricity is consumed

So

Consumption Energy
charge
Units units Rate

0-20 4 20 80
21-30 7 10 70

31-50 8.5 20 170

51-x x-50 10 (x-50)10

Total energy charge =220+10(x-51)

Service charge = 125

Total charge = Energy charge + service charge

945= 10x-
945+155=10x
1000=10x
X=100

Page 62 Q 7a) Total consumptions =1675-1050=325
It lies in 251-400

UNITS B W RATE T E C

0-20 20 3 60

21-30 10 7 70

31-50 20 8.5 170

51-150 100 10 1000

151-250 100 11 1100

250-400 75 12 900

3300

= energy charge + service charge
=3300+150=3450

Q 8 ) Total consumption =125
It lies in 51-150

UNITS BW RATE TEC
0-20 20 3 60
21-30 10 7 70
31-50 20 8.5 170
51-150 75 10 750
total 1050

Total coat =energy charge + service charge

=1050+100=1150

Bill payment =1150-3%of 1150
=1150-0.03*1150
=1018.5

Page 73 QN 10 A

Total Cost =600
Cost of first minutes =Rs200additiona rate =Rs 20
per 15 second
Let duration of additions call=x second
We have ,

Total charge =charge of first call +additional charge

Total minutes=5 minutes

Total duration =duration of first kind+ duration of second kind

Total time =1minutes +5minutes
=6minutes

So, Man calls for 6 minutes
QN 11A page 73
Rate of first kind =Rs 3 for2 per minutes
Rate of second kind (extra calls)=Rs 3 per minutes
Let men call minutes for second kind
Total charge = minimum + extra charge

Total duration = first kind + second kind
=2+14
=16

PAGE 67 Q 2A

Type Of Pipe ½ INCH
minimum charge Rs100
rate of extra units Rs32
minimum units 10
total consumption 30units

Extra units = total consumption –m

=30-10 =20

Extra charge= 20*32
=640

Total charge= minimum +extra
=100+640
=740

Total charge of water is Rs 740

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minimum units

PAGE 67 Q 3A ½ INCH
Type Of Pipe Rs100
minimum charge Rs32
rate of extra units 10
minimum units Current readi
total consumption =1634—1534

Extra units = total consumption –m

=100-10 =900

Extra charge= 90*32
=2880

Total charge= minimum +extra
=100+2880
=2980

Total charge of water is Rs 2980

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ing-previous reading
4=100

minimum units

PAGE 67 Q 4A 1 Inch
Type Of Pipe Rs3960
minimum charge Rs71
rate of extra units 56
minimum units 18160
total charge

Extra units = total consumption –m

=x-56

Extra charge= 71*(x-56)

Total charge= minimum +extra
18160=3960+71(x-56)
14200=71(x-56)
200=x-56
x=256

Total consumption of water is

minimum units
s 256units

PAGE 67 Q 6A

Type Of Pipe 1/2 Inch

minimum charge Rs100

rate of extra units Rs32

minimum units 10 units

total consumption Current readi
=2690-2540
=150

Extra units = total consumption –m

=150-10=140

Extra charge= 32*140=4480

subTotal charge= minimum +extra
=100+4480
=4580

If 5% sewage charge
Total charge =4580+5% of4580

=4809

ing –previous reading

minimum units

If bill is paid on the first m
3%rebate

Bill of payment =4809-3%of480

=664.72

If bill is paid on the third
rebate no fine

Total bill=4809

If bill is paid on the 6th mo
Bill to pay=4809+50%of480

=7216.5

month there is

09

month there is no

onth there is 50% fine
09