Why is it preferable to measure a penny in millimeters rather than centimeters or meters?

Because you will get whole numbers in milimeters.

Step-by-step explanation:

Since a penny is small, you would need to use small units to measure it, otherwise you will end up with a scientific notation number, or with large decimals in order to be able to express its measurements, with milimeters you will only get whole numbers and can be more exact.

75 tickets have been sold so far.

step-by-step explanation:

in this question it is clearly mentioned that 45 children's tickets have been sold and this number is 60% of the total tickets sold.

now let's assume the total number of tickets sold be x.

then 60% of x = 45

⇒

⇒ x(.6) = 45

by dividing with .6 on both the sides of the equation

⇒ x = 75

therefore 75 tickets have been sold so far.

step-by-step explanation: