The radius of a plate is 9.7 centimetres correct to the nearest millimetre. Write down the least possible length it could be

Question

its to do with lower bounds and upper bounds but I’m not sure how to do it

Answer 1

The radius of a plate is 9.7 centimetres correct to the nearest millimetre. Write down the least possible length it could be

​Let the radius be 97 millimetres.

Assuming that you are rounding off values, then ...

A fractional value of 0.5 or above will round up to the next integer value.

A fractional value of less than 0.5 will round down to the integer value below.

So your radius will range from 96.5 to 97.4 mm (to 1 d.p.)

So, least possible length is R = 9.65 cm