Question

a man wanted to exchange rs 1000 in 2 types of notes of rs 5 and rs 19 denominations if he had 180 notes in all find the number of notes of each kind ​

Answer 1

Answer:

The man would need 160 rs5 notes and 20 rs19 notes to exchange rs1000.

Step-by-step explanation:

This is a problem on linear equations.

lets say there are x no. of rs5 dominations.

and y no. of rs19 dominations are required to make rs1000.

Firstly, we know from the problem x + y = 180 in total notes of both dominations.

so, y = 180 - x -------- (1)

Also, we know that the notes domination sum up to rs1000 i.e 5x + 19y = 1000; -------- (2)

Substitution of the value of y in eq 2, using eq 1

5x + 9 (180-x) = 1000

=> 5x + 1620 - 9x = 1000

=> 5x - 9x = 1000-1620

=> -4x = -620

=> x = -620 ÷ -4

=> x = 320 ÷ 2

=> x = 160

Using eq 1 substitute the value of x = 160,

y = 180 - 160 = 20.

which gives us the answer, the man would need 160 rs5 notes and 20 rs19 notes to exchange rs1000.