Question

meena went to a bank to withdraw rs 2000. she asked the cashier to given her rs.50 and rs 100 notes only . meena got 25 notes in all . find how many notes rs 50 and rs 100 she reserved ​

Answer 1

Let no. of Rs. 50 notes = x

no. of Rs. 100 notes = y

Total notes = 25

Xty= 25

x = 25-y

total amount only in Rs. 50 notes = 50x

total amount only in Rs. 100 notes = 100y

Total amount 2000

50x +100y 2000

50(25-y)+100y 2000

50x25-50y + 100y = 2000

1250 +50 y = 2000

50y= 2000-1250 = 750

y= 750/50 = 15

x= 25-15 = 10

No. of Rs. 50 notes = 10

No. of Rs. 100 note

ᴘʟᴢ ʀᴀᴛᴇ ᴍʏ ᴀɴsᴡᴇʀ

Answer 2

$\huge \sf Answer :$

Rs 50 notes = 10 and Rs 100 notes = 15

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$\huge \sf Solution :$

Let total Rs 50 notes = x

and total Rs 100 notes = y

∴ Total notes = x + y

But we are given total notes = 25

$\sf \implies x+y = 25 \: \: - ①$

Now, Meena has total money =50x + 100y

But we are given total money =Rs 2000

$\sf \implies 50x+100y=2000$

$\sf \implies 50(x+2y)=2000$

$\sf \implies x+2y = \dfrac{2000}{50}$

$\sf \implies x+2y = \dfrac{\cancel{2000}^{40}}{\cancel{50}}$

$\sf \implies x+2y = 40 \: \: - ②$

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On substraction of ① and ②,

(x+y) - (x+2y) = 25 - 40

x + y - x - 2y = - 15

- y = - 15

$\boxed{\sf y = 15}$ ⠀

Now, by putting y in ①,

x+y=25

x + 15 = 25

x = 25 - 15

$\boxed{\sf x=10}$

∴ Rs 50 notes, x = 10

and Rs 100 notes, y = 15