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
Answers
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.