Question

12) A spool has a diameter of 3.5 cm. If a string
makes 15 turns around it, what is its length?​

Answer 1

Answer:

145cm is the length

Step-by-step explanation:

To take out the length of string, multiply the perimeter of the pool to 15.

perimeter (circumference) = 2πr

                                           = 2 x 22/7 x 3.5/2

                                           = 11cm

Length of string = 15 x 11

                          = 145cm

Answer 2

Answer:

Given:

diameter = 3.5 cm

The string makes turns around it, therefore circumference should be calculated.

Since the string makes 15 turns around it, our required answer for the length will be 15 times the circumference.

circumference = 2πr OR πd        ( since we have d, we will use πd )

                         = 22/7 × 3.5

                         = 22 * 1/2         ( 7 × 1/2 = 3.5 )

                         = 11 cm

Length of string = 11 × 15

                            = 165 cm or 1.65 m

Therefore, the length of the string is 1.65 m.