Q14 of 80 Page 42

A sum of ₨ 500 is in the form of denominations of ₨ 5 and ₨ 10. If the total number of notes is 90 find the number of notes of each denomination.

(Hint: let the number of 5 rupee notes be ‘x’, then number of 10 rupee notes = 90–x)

There are a total of 90 notes of Rs 5 and Rs 10 together.

Let the number of 5 rupee notes be x.


∴ The number of 10 rupee notes = 90 – x.


The total amount = Rs 500.


According to the given condition,


5x + 10 (90 – x) = 500


⇒ 5x + 900 – 10x = 500 (Removing bracket)


-5x + 900 = 500


⇒ -5x = 500 – 900 (Transposing 900 to RHS)


-5x = -400


⇒ x = (Transposing -5 to RHS)


x = 80


The number of 5 rupee notes = x = 80.


The number of 10 rupee notes = 90 – x = 90 – 80 = 10


∴ The number of 5 rupee and 10 rupee notes are 80 and 10 respectively.


More from this chapter

All 80 →
12

The ages of Rahul and Laxmi are in the ratio 5:7. Four years later, the sum of their ages will be 56 years. What are their present ages?

 13

There are 180 multiple choice questions in a test. A candidate gets 4 marks for every correct answer, and for every un-attempted or wrongly answered questions one mark is deducted from the total score of correct answers. If a candidate scored 450 marks in the test how many questions did he answer correctly?

 1

Solve the following equation:

7x – 5 = 2x

 2

Solve the following equation:

5x – 12 = 2x – 6