Answer:
9. (a) 1/4
(b) remove 3 alphabet cards
(c) add 4 number cards
10. 1/8
Explanation:
Question 9
Given:
- 8 number cards
- 10 alphabet cards
- 6 picture cards
⇒ total number of cards = 8 + 10 + 6 = 24 cards
(a) P(picture card) = 6/24 = 1/4
(b) P(alphabet card) = 10/24 = 5/12
If we remove 3 alphabet cards from the box
⇒ number of alphabet cards = 10 - 3 = 7
⇒ total number of cards = 24 - 3 = 21
Therefore, P(alphabet card) = 7/21 = 1/3
(c) P(number card) = 8/24 = 1/3
If we add 4 number cards to the box:
⇒ number of number cards = 8 + 4 = 12
⇒ total number of cards = 24 + 4 = 28
Therefore, P(number card) = 12/28 = 3/7
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Question 10
Given:
- ΔSDR = ΔPRQ
- Leg length of ΔSDR and ΔPRQ = 4 cm
⇒ area of ΔSDR = area of ΔPRQ = 1/2 × 4 × 4 = 8 cm²
As PR = SD = 4cm
Area of rectangle = (4 + 4) × (12 + 4) = 128 cm²
P(point lies in ΔSDR) = 8/128 = 1/16
P(point lies in ΔPRQ) = 8/128 = 1/16
P(point lies in ΔSDR) OR P(point lies in ΔPRQ) = 1/16 + 1/16 = 2/16 = 1/8