Local Quiz

[corriebear1]

Help needed please

I am painting the bedrooms in my house with some paint I’d bought just for that job.



At one point, I’d painted exactly half of the first room of 32 square metres of wall/ceiling with one coat of paint and used an eigth of a brand new 2litre tin of paint. I then finished the first coat.



Once I’ve put a second coat on that room, I’ll start a bigger room with walls/ceiling of 48 square metres.



How many ml will I have left after one coat to the second room?



(assume that there is even coverage and no waste)

[Murphysrocks]

Alright, I'll give it a try ....
Painting the 1st half of the 32 square metres took 1/8 of a 2-litre tin of paint. That's 1/4 of a litre of paint.
Painting the 2nd half of it will take the same amount as the 1st half did, or 1/4 of a litre.
So it'll take a total of 1/2 a litre of paint to do 1 coat of the 1st room.
And you want to do a 2nd coat of that room, so that'll take another 1/2 a litre of paint.
Then you want to do a 1st coat of the 48 square metres room, which is 50% bigger than the 32 square metres room.
So that'll take 50% more paint than was needed to coat the 1st room (which took 1/2 of a litre). So that'll take 3/4 of a litre.
So you'll have used 1/2 a litre of paint on the 1st room, and 3/4 of a litre on the 2nd room, for a total of 1 and 1/4 litres.
So in the end, there'll be 3/4 of a litre, or 750 mls, of paint left in your 2-litre tin.

[margarettom]

1/8th of 2000ml = 250ml so to paint whole room with 1 coat takes 500ml. After 2nd coat 1000ml used.

32 sq m uses 250ml for 1 coat
1 sq m uses 250 ml divided by 32 ml
48 sq m uses 250ml divided by 32 x 48 = 375 ml

So amount left in tin is 2000 - 1000 - 375 ml = 625 ml

[Murphysrocks]

I think we both went wrong, Margarettom. :)
I forgot to include the 2nd coat of the 1st room in my total, so "you'll have used 1/2 a litre of paint on the 1st room" should say "1 litre".
3/4 of a litre on the 2nd room makes a total of 1 and 3/4 litres.
So 1/4 litre or 250 ml left.
And in your sums, "32 sq m uses 250 ml" should say "500 ml", because the 250 ml was only for half of the 1st coat.
So 1 sq m uses 500 ml / 32.
48 sq m uses 500 ml / 32 x 48 = 750.
2000 - 1000 - 750 = 250.
So we both end up with 250 ml left.
But I'm open to further correction.

[margarettom]

Seems good to me Murphysrocks. Two wrongs made a right for once!!

[corriebear1]

thanks appreciate it