Question

18. एक परीक्षा में, जिसमें पूर्णांक 500 थे, A को B की अपेक्षा 10% कम
अंक मिले। उसी में B को C की अपेक्षा 25% अधिक अंक मिले और
को D की अपेक्षा 20% कम अंक मिले। तद्नुसार, यदि A को 360 अंक
मिले हों, तो D को पूर्णांक के कितने प्रतिशत अंक प्राप्त हुए थे?
(a)90%
(b) 80% (C) 50% (d) 60%​

Answer 1

Answer:

Procedure

Take some fine soll in a flat container

12) Add some water to it to form soft mud.

13) Keep the container on the floor near the table.

(41 Keep the wooden block and iron block on the table and push them gently one at a time in such a way

that they fall on the mud in the container

(5) Observe the impressions produced by the blocks in the mud in t

(a) The condition before the blocks fall on the mud (b) The condition after the blocks fall on the mud

Answer 2

Answer:

Let A gets 90n in the exam

▣ Marks obtained by B :

⇴ A = B × (100 - 10)%

⇴ 90n = B × 90 / 100

⇴ 90n × 100 / 90 = B

⇴ n × 100 = B

⇴ B = 100n

▣ Marks obtained by C :

⇴ B = C × (100 + 25)%

⇴ 100n = C × 125 / 100

⇴ 100n × 100 / 125 = C

⇴ 100n × 4 / 5 = C

⇴ 20n × 4 = C

⇴ C = 80n

▣ Marks obtained by D

⇴ C = D × (100 - 20)%

⇴ 80n = D × 80 / 100

⇴ 80n × 100 / 80 = D

⇴ n × 100 = D

⇴ D = 100n

⠀⠀⠀⠀⠀───────────────

• Given in the Question :

⇢ A = 360 marks

⇢ 90n = 360 marks

⇢ n = 360 marks / 90

⇢ n = 40 marks

• Marks obtained by D :

⇢ D = 100n

⇢ D = 100 × 40 marks

⇢ D = 400 marks

• Percentage of D in Exam :

⇢ D Percentage = D Marks / Total × 100

⇢ D Percentage = 400 / 500 × 100

⇢ D Percentage = 4 / 5 × 100

⇢ D Percentage = 4 × 20

⇢ D Percentage = 80%

∴ Percentage of D in exam is b) 80%.