Joan makes cups of tea and coffee at a lunch club Each cup requires 250 ml of boiling water.
She has a kettle that boils up to 1.7 litres of water each time.
She boils 10 litres of water in an urn.
She then uses the kettle to boil the rest of the water she needs.
Find the least number of times that Joan needs to boil the kettle to make 56 cups.
Show how you decide.

idk

step-by-step explanation:

b) yes

step-by-step explanation:

let the statements be named as,

statement 1: if the power has been cut, then the refrigerator does not work.

statement 2: the refrigerator does not work.

conclusion: the power has been cut

now, 'law of detachment states that if we have the statements given as,

1. if p, then q.

2. p

then, we get the true statement or conclusion as q'.

thus, on comparing, we get that,

p: if the power has been cut.

q: the refrigerator does not work.

so, the argument is true by the law of detachment.