A carpenter had a piece of wood that was 15 feet in length. If he needs only 10 &five twelfth feet of wood, then how much wood should he cut ?

12.5 feet

Step-by-step explanation:

He only needs 10/12 of a 15 foot long piece of wood. We need to find 10/12 of the length of the wood.

That is:

10/12 * 15 = 12.5 feet

He only needs 12.5 feet of the piece of wood.

25.

Step-by-step explanation:

Let the number of pupils be x, then:

there are 0.6x girls and 0.4x boys.

From the given information:

0.6x - 0.4x = 5

0.2x = 5

x = 5/0.2

= 50/2

= 25.