Trying the figure out last question!

Question

There are 107 stamps in the book. There are twice as many 10 cent stamps as there are 5 cent stamps. The number of 25cent stamps is two more than the number of 10 cent stamps. Find the number of each type of stamp that are in the boo

Answer 1

n=number of 5 cent stamps

d= number of 10 cent stamps

q = number of 26 cent stamps

 

Since there are a total of 107 stamps, 

n+ d +q =107

 

It is given that, there are twice as many 10 cent stamps as there are 5 cent stamps.

d = 2n

if you divide both the sides by 2, 

n = d/2

 

Also given is that the number of 25cent stamps is two more than the number of 10 cent stamps

q=d+2

 

 

You can see that n and q can now be expressed as d. So, you can now plug these two in the equation above

 

n+ d +q =107

d/2 + d + d + 2= 107

d/2 + 2d = 107-2 = 105

Now multiplying both the sides by 2

d+ 4d = 210

5d=210

d = 210/5

d=42

n= d/2 = 42/2=21

q = d+2= 42+2=44

 

Now, when n, d, and q are added

21+42+44=7

 

There are 21 5 cent stamps, 42 10 cent stamps, and 44 25 cent stamps.