Question

Bharti has a number of 2 and 5 coins in her purse. If the number
of 2 coins is double the number of 5 coins and the total amount
is 144, find the number of 2 and 5 coins each.​

Answer 1

Let number of coins be x

Let number of 2₹ coins be a

Let number of 5₹ coins be b

ATQ:

Number of 2₹ coins + Number of 5₹ coins = 144₹ Total

∴ 2₹(a) + 5₹(b) = 144                               ...(1)

Also, Number of 2₹ coins = Twice the number of 5₹ coins

a = 2x                                                      ...(2)

b = x                                                        ...(3)

Now, substituting (2) and (3) in (1), we get:

2₹(2x) + 5₹(x) = 144₹

Now, Solving for x:

4x + 5x = 144

9x = 144

x = 144/9

x = 16                                                        ...(4)

Now that we have obtained value of x, we can substitute (4) into (2) and (3):

a = 2x

a = 2(16)

a = 32

Also,

b = x

b = 16

Therefore, Bharti has 32 2₹ coins and 16 5₹ coins in her purse.

Verifying answer by substituting values of a and b into (1):

2₹(a) + 5₹(b) = 144₹

2₹(32) + 5₹(16) = 144₹

64₹ + 80₹ = 144₹

144₹ = 144₹

Hence proved.

Hope this helped! Stay Safe & Stay Sanitized! <3