Question

If 1/8 of a pencil is black, 1/2 of the remaining is white and the remaining is 7/2cm is blue, find the Total length of the pencil
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Answer 1

Answer:

Let total length of pencil be x cm.

Then, black part = x/8

Remaining part pencil after black part = x - x/8 = 7x/8

then White part = 1/2 (7x/8)  

= 7x/16

Now Remaining part of pencil is blue = total length of pencil - (length of black part + length of white part)

length of blue part of pencil = x - (x/8 + 7x/16)

length of blue part of pencil = x - (2x + 7x)/16

length of blue part of pencil = x - 9x/16

length of blue part of pencil = (16 x - 9x)/16

∴ Length of blue part = 7x/16;

According to question

Length of blue part = 31/2  

7x/16 = 31/2  

⇒ 7x/16 = 7/2

⇒ x/16 = 1/2

⇒ x = 16/2

∴ x = 8 cm

Step-by-step explanation:

Answer 2

Answer:

Let total length of pencil be x cm.

Then, black part = x/8

Remaining part pencil after black part = x - x/8 = 7x/8

then White part = 1/2 (7x/8)  

= 7x/16

Now Remaining part of pencil is blue = total length of pencil - (length of black part + length of white part)

length of blue part of pencil = x - (x/8 + 7x/16)

length of blue part of pencil = x - (2x + 7x)/16

length of blue part of pencil = x - 9x/16

length of blue part of pencil = (16 x - 9x)/16

∴ Length of blue part = 7x/16;

According to question

Length of blue part = 31/2  

7x/16 = 31/2  

⇒ 7x/16 = 7/2

⇒ x/16 = 1/2

⇒ x = 16/2

∴ x = 8 cm

Step-by-step explanation: