Question

A sum of rs 36.90 is made up of 90 coins that are either 20 paise coins or 50 paise coins. find out how many 20 paise coins are there in the total amount ?

Answer 1

hey friend
here is your answer
let coins of 20 paisa be x
and let coins of 50 paisa be y
convert the 36. 90 RS in paisa
it will be 3690 paisa
means
20x+50y=3690 ..................... (1)
x+y=90 .......................... (2)
multiply (2) by 50 on both sides we get
50x+50y=4500
subtract (2) from (1)
20x+50y=3690
50x+50y=4500
-30x=-810
x=-810/-30
x=27
the number of coins of 20 paisa are 27
please mark me as brainliest

Answer 2

There are 27 coins of worth 20 paise.

Given - Sum and number of coins

Find - Number of 20 paise coins

Solution - Let there be x number of 20 paise coins. So, number of 50 paise coins will be (90 - x).

We know, 1 Re = 100 paise. So,

Value of 20 Paise coins in Rupees = Re 0.2

Value of 50 paise coins in Rupees = Re 0.5

As per the given information, the equation that will form is -

0.2*x + 0.5*(90 - x) = 36.90

Performing multiplication

0.2x + 45 - 0.5x = 36.90

Performing subtraction

- 0.3x + 45 = 36.90

Shifting values on other side of equation

45 - 36.90 = 0.3x

Performing subtraction

8.1 = 0.3x

x = 8.1/0.3

Performing division

x = 27

So, number of 50 paise coins = 90 - 27

Performing subtraction

Number of 50 paise coins = 63

So, there are 27 coins worth of 20 paise.

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