Each tweet would cost between 1 and 140 pennies you can write that as an inequality [1 ≤ x ≤ 140] Since you can't tweet 0 characters or above 140.
if you want to change it to pounds divide by 100.
A) 1 ≤ x ≤ 140
B) Each character costs a penny, you can't tweet less than 1 character or above 140.