Question

Meena went to a bank to withdraw rs. 2000. she asked the cashier to give her rs.50 and rs.100 notes only. meena got 25 notes in all. find how many notes of rs.50 and rs.100 she received

Answer 1

10 notes of ₹50 and 15 notes of ₹100

Answer 2

$\huge\sf{\underline{\underline{Solution:}}}$

• first number be = x

• second number be = y

A.T.Q

⟹ 2(x) + 3(y) = 61

⟹ 2x + 3y = 61 ...(1)

Now,

⟹ 4(x) - 5(y) = 45

⟹ 4x - 5y = 45 ...(2)

Multiply equation 1 with equation 2

→ 2x + 3y = 61 (×2)

→ 4x + 6y = 122

→ 4x = 122 - 6y ...(3)

Substitute value of 4x in (equation 2)

⟹ 122 - 6y - 5y = 45

⟹ - 11y = 122 - 45

⟹ - 11y = - 77

⟹ y = 7

Substitute value of y in (equation 1)

⟹ 2x + 3(7) = 61

⟹ 2x + 21 = 61

⟹ 2x = 61 - 21

⟹ 2x = 40

⟹ x = 20

∴  First number = x = 20 

 Second number = y = 7