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Solution: (a) Marks given for each correct answer = 5

So, marks given for 10 correct answers = 5 × 10 = 50
Q Radhika’s score = 30
\ Marks obtained for incorrect answers = 30 – 50 = –20
Now, marks given for each incorrect answer = (–2)

Therefore, the number of incorrect answers = (–20) ÷ (–2) = 10
(b) Marks given for 4 correct answers = 5 × 4 = 20
Q Jay’s score = –12

\ Marks obtained for incorrect answers = –12 – 20 = –32
Also, marks given for one incorrect answer = (–2)
Therefore, the number of incorrect answers = (–32) ÷ (–2) = 16

Practice Time 1C

1. Divide the following.

(a) 28 by (–7) (b) (–14) by 2 (c) 32 by 4 (d) (–125) by (–25)
(e) (–72) by 72
2. Determine the quotient for each of the following.
(a) (–51) ÷ (+3) (b) 36 ÷ (–18) (c) 232 ÷ (–8) (d) 0 ÷ (–115)
(e) (–144) ÷ 12 (f) (–200) ÷ 10 (g) 4050 ÷ (–18)
3. Fill in the blanks.
(a) (–101) ÷ ....... = 1 (b) ....... ÷ 34 = –1 (c) ....... ÷ (–9) = 9 (d) 256 ÷ (–16) = .......
4. Simplify the following.
(a) [(–6) + 5] ÷ [(–2) + 1] (b) –|(–630) ÷ (–7)|

(c) |117 ÷ (–13)| – |(–119) ÷ 17)| (d) [(–24) ÷ (–12)] ÷ 4
5. An integer when divided by (–4), gives 36. Find the integer.
6. The product of two integers is 288. If one of them is –12, find the other.
7. The temperature of a hill station at 12 noon was 12°C above zero. It decreases at the rate of 1.5°C
per hour until midnight.
(a) At what time will the temperature be 6°C below zero?
(b) What will be the temperature at midnight?
8. In a test, (+3) marks are awarded for every correct answer and (–0.5) marks are deducted for
every incorrect answer.
(a) Roma answered all questions. She got 10 correct answers and scored 24 marks. How many answers
were incorrect?
(b) Ruhi got 4 correct answers. Her score was 3. How many total number of questions had she
attempted?
9. A shopkeeper earns a profit of `2 by selling one pen and incurs a loss of 15 paise per pencil while
selling pencils of old stock.
(a) In one month, he incurs a loss of `8 on selling 32 pens. How many pencils did he sell?
(b) In the next month, on selling 6 dozen of pens, he earns neither profit nor loss. How many pencils
did he sell?

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