**1. A certain freezing process requires that room temperature be lowered from 50**

^{0}C at the rate of 5^{0}C every hour. What will be the room temperature 10 hours after the process begins?

**2. A merchant on selling rice earns a profit of Rs. 20 per bag of fine rice sold and loss Rs. 10 per bag of non-fine rice.**

**i) He sells 5000 bags of fine rice and 3000 bags of non – fine rice in a month. What is his profit or loss in the month?**

**ii)What is the number of Fine rice bags he must sell to have neither profit nor loss, if the number of bags of non-fine rice sold is 6,400.**

**3. A cement company earns a profit of Rs. 10 per bag of white cement sold and a loss of Rs. 5 per bag of grey cement sold.**

**i) He company sells 8000 bags of white cement and 6000 bags of grey cement in a month. What is its profit or loss?**

**ii) What is the number of white cement bags it must sell to have neither profit nor loss, if the number of grey bags sold is 5,400**

**4. The temperature at 12 noon was 10**

^{0 }C above zero. If it decreases at the rate of 2^{0}C per hour until mid-night at what time would the temperature be 6^{0}C below zero. What would be the temperature at mid-night ?

**5. In a class test (+3) marks are given for eery correct answer and (-2) marks are given for every incorrect answer and no marks for not attempting any question.**

**i) Radhika scored 20 marks. If she has got 12 correct answers, how many questions has she attempted incorrectly?**

**ii) Mohini scores (-5) marks in this test, though she has got 7 correct answers. How many questions has she attempted incorrectly.**

**6. An elevator descends into a mine shaft at the rate of 6 meters per minute. If the descent stars from 10m above the ground level. How long will it take to reach – 350m**

**7. Krishna deposited Rs. 100 with her mother. He withdraws Rs. 50 from her mother on the next now what is the money with his mother?**

**8. There is a class test for 25 marks. Sheeta lost 10 marks and Gopi lost 8 marks. What were marks at the test?**

**9. In a freezing process the temperature is to be lowered to 20**

^{0}C. If the room temperature 30^{0}C, how much it should be reduced?

**10. Simplify -1-2-3-……(-20)**

**11. Ram won 10 marbles in a game on a particular day. He lost 3,5,6 and 8 on the following Find his net gain or loss.**

**12. A Fine of Rs. 5 is collected on every Rs. 100 to be deposited with post office. What was the fine a sum of Rs. 1200 ?**

**13. In a test of 15 Questions, every correct answer gets 5 marks and every wrong answers was get (-2) marks. Rama answered all questions, out of which 8 are correct what is his total score?**

**14. In a quiz every right answer carries 10 marks and every wrong answer (2) marks. It a total of 12 questions were asked of which 8 are correct, find the total score.**

**15. A fruit seller gains Rs. 200 on every dozen mangoes sold and loses Rs. 25 on every dozen apples sold. If he sells 5 dozen mangoes and 10 dozen apples, what is his net gain or loss on the whole transactions?**

Om Sri Ram Om Sri Ram Om Sri Ram

1. A certain
freezing process requires that room temperature be lowered from 45

^{0}C at the rate of 5^{0}C every hour. What will be the room temperature 10 hours after the process begins?
Sol. The
present room temperature = 45

^{0}
Total decrease of temperature 10
houurs = 10 x5

^{0}=50^{0}
Temprature afer 10 years = 40

^{0}-45^{0}= 5^{0}
2. A merchant on selling rice earns a profit of Rs. 20 per
bag of fine rice sold and loss Rs. 10
per bag of non-fine rice.

i) He sells
5000 bags of fine rice and 3000 bags of non – fine rice in a month. What is his profit or loss in the month?

Profit on
5000 bags of fine Rice = 5000 x 20 =1,00,000

Profit on
3000 bags on nonfine rice= 3000 x 10 = 30,000

Net profit =
100,000 -30,000= 70,000

ii)What is
the number of Fine rice bags he must sell to have neither profit nor loss, if
the number of bags of non-faine rice sold is 6,400.

Profit on
fine rice = Loss on non-fine rice

But lloss on
non fine rice = 6400 x 10 = 64000

No. of bags
of fine rice sold = 64000/20 = 3,200

3. A cement
company earns a profit of Rs. 10 per bag of white cement sold and a loss of Rs.
5 per bag of grey cement sold.

i)
He
company sells 8000 bags of white cement and 6000 bags of grey cement in a
month. What is its profit or loss?

Sol. Profit on 8000 white cement bags = 8000 x 10 = 80,000

Loss on 6000
grey cement bags = 6000 x 5 = 30,000

Net profit = 80,000 =- 30,000 = 50,000 Profit.

ii)
What
is the number of white cement bags it must sell to have neither profit nor
loss, if the number of grey bags sold is 5,400

Profit on white cement
bags = loss on grey cement bags.

Loss on grey cement
bags = 5 x 5400 = 27,000

Number of white cement
bags : 27,000/10 = 2700

4. The
temperature at 12 noon was 10

^{0 }C above zero. If it decreases at the rate of 2^{0}C per hour until mid-night at what time would the temperature be 6^{0}C below zero. What would be the temperature at mid-night ?
Sol. The
temperature at 12 noon = 10

^{0}^{ }Given temperature = -6

^{0}C

Diff. between the temperature =

^{ }10^{0}– (-6^{0}) = 16^{0}
Time lasted = 16 /2 =8

^{0}
5. In a
class test (+3) marks are given for every correct answer and (-2) marks are
given for every incorrect answer and no marks for not attempting any question.

i) Radhika
scored 20 marks. If she has got 12
correct answers, how many questions has she attempted incorrectly?

Sol. Radhika’s
score = 20

No. of correct answers = 12

And marks for correct answers = 12 x 3
=36

Marks for incorrect answers = 36-20 =
18

Number of incorrect answers = 18/2 =9

ii) Mohini scores (-5) marks in this test, though she has
got 7 correct answers. How many
questions has she attempted incorrectly.

Mohini’s
score = -5

Marks for
correct answers = 7 x 3 = 21

Marks for
incorrect answers = -5 -21 = -26

Number of
incorrect answers = -26/2 = -13

6. An elevator
descends into a mine shaft at the rate of 6 meters per minute. If the
descent stars from 10m above the ground level. How long will it take to reach – 350m

Sol. Total
length to be descend = -350 -10 = -360m

Rate of the speed of the elevator = 6m
per minute

Total time to descend = 360/6 = 60
minuts = 1 hour

7. Krishna
deposited Rs. 100 with her mother. He
withdraws Rs. 50 from her mother on the next now what is the money with his
mother?

Sol. Money
deposited = Rs. 100

Money With drawn = Rs 50

Money withmother = Rs. 100 - 50 =Rs. 50

8. There is
a class test for 25 marks. Sheeta lost
10 marks and Gopi lost 8 marks. What
were marks at the test?

Sol. Total
marks for the test = 25

Marks lost by sheetal = 10

Sheetal’s marks = 25-10 = 15

Marks lost by Gopi = 8

Gopi marks = 25 -8
= 17

9. In a
freezing process the temperature is to be lowered to 20

^{0}C. If the room temperature 30^{0}C, how much it should be reduced?
sol.
Required temperature = -20

^{0}
Room Temparature = 30

^{0}
The temperature to be reduced by = 30
–(-20)= 50

^{0}C
10.
Simplify -1-2-3-……(-20)

(-1-20)+(-2-19)+(-3-18)+(-4-17)+(-5-16)+(-6-15)+(-7-14)+

(-8-13)+ (-9-12) +(-10-11) = 10 x (-21) =-210

11. Ram won
10 marbles in a game on a particular day.
He lost 3,5,6 and 8 on the following Find his net gain or loss.

Numbers of
marbles won by ram =10

Number of
marbles lost by Ram = 3+5+6+8 =22

Net loss =
10 -22 =-12

12. A Fine
of Rs. 5 is collected on every Rs. 100 to be deposited with post office. What
was the fine a sum of Rs. 1200 ?

For every
hundred thefine is Rs. 5

For Rs. 1200
the fine = 5 x 12 = Rs. 60

13. In a
test of 15 Questions, every correct answer gets 5 marks and every wrong answers
was get (-2) marks. Rama answered all
questions, out of which 8 are correct what is his total score?

Number of
correct answers = 8

Marks for 8
correct answers = 8 x 5 = 40

Number of
wrong answers = 15-8= 7

Marks for
wrong answers = 7 x (-2) = -14

Total Marks
= 40 + (-14) = 26

14. In a
quiz every right answer carries 10 marks and every wrong answer (-2)
marks. It a total of 12 questions were asked
of which 8 are correct, find the total score.

Sol. Right
answers = 8

Marks for
right answers = 8 x 10 = 80

Wrong
answers = 4

Marks for
wrong answers = 4 x (-2) = -8

Total marks
= 80 – 8= 72

15. A fruit
seller gains Rs. 200 on every dozen mangoes sold and loses Rs. 25 on every
dozen apples sold. If he sells 5 dozen
mangoes and 10 dozen apples, what is his net gain or loss on the whole
transactions?

Gain 5 dozen
mangos = 5 x 200 = 1000

Loss on 10
dozen apples = 10 x 25 =250

Net
gain = Rs. 1000 – 250 = Rs. 750