A piece of string is 3-5 m long. Joe cuts three pieces from it, each 70 cm long. How much of the original piece is left?

Note: It seems you mean a piece of string is 3.5 long. So,  I am assuming that a piece of string is 3.5 cm long.

140 cm of the original piece is left after Joe cuts three pieces.

Step-by-step explanation:

Given the piece of string

As we know that

so the length of a piece of string = 350 cm

As joe cuts three pieces from it, and each 70 cm long.

so the total length of three pieces which were

cut by joe = 70cm + 70cm + 70cm = 210 cm

So, subtracting the total length of the three pieces that were cut from the total length of the string:

350 cm - 210 cm = 140 cm

Therefore, 140 cm of the original piece is left after Joe cuts three pieces from it.

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls