Question 1022702: 200 coins. Consisting of 1php and 25 centavos. If you add all the 1php and 25c the sum is 95php. How many coins of each kind are there? Answer by Edwin McCravy(20060) (Show Source):
I do not know your money system. So I'm guessing.
Let the number of 1phps be x
Let the number of 25centavos be y
Value Value
Type Number of of
of of EACH ALL
coin coins coin coins
-------------------------------------------
1phps x 1php 1x php
25centavos y 0.25php 0.25y php
-------------------------------------------
TOTALS 200 ----- 95 php
The first equation comes from the second column.
x + y = 200
The second equation comes from the last column.
1x + 0.25y = 95
Get rid of decimals by multiplying every term by 100:
100x + 25y = 9500
So we have the system of equations:
.
We solve by substitution. Solve the first equation for y:
x + y = 200
y = 200 - x
Substitute (200 - x) for y in 100x + 25y = 9500
100x + 25(200 - x) = 9500
100x + 5000 - 25x = 9500
75x + 5000 = 9500
75x = 4500
x = 60 = the number of 1phps.
Substitute in y = 200 - x
y = 200 - (60)
y = 140 25centavos.
Edwin
