A piece of wood is of length 45 cm the length is divided in the ratio 7:2 work out the length of each part

Question

United kingdom 

Answer 1

45 cm piece of wood divided in the ratio of 7:2

7x and 2x are the lengths

7x+2x=45

9x=45

x=45/9

x=5

5*7=35 cm

5*2=10 cm

35/10=7/2

 

piece 1        piece 2

   7                 2

   14               4

   21               6

   28               8

   35               10                 35+10=45

 

Answer 2

Hi Ashmi--

 

Since the ratio is 7:2, you can start by thinking of it as 9 pieces. If you divided the board into 9 equal pieces, they'd each 5 inches long, because 45 divided by 9 = 5.

 

But since they're in the 7:2 ratio, you have (7 x 5) to (2 x 5), or 35:10

 

So one is 35 inches, the other is 10.

 

In simpler words, it's 7x + 2x = 45. (So 9x = 45, and x = 5. So 7x = 35, and 2x = 10.)

 

Hope this makes sense!

 

Matt in NY