Question

Q 3; 6 and 7please do it quick
only answer if you know​

Answer 1

Q3) 1000/193 is nearly 5.

Therefore, the salt in thousand kg of seawater is

$7 \times 5 = 35kg$

Q6) The smallest number of marbles you must remove from the set of having two of the same colour is 6.

This is because in first 5 times we can get marbles of all five different colours but at the 6th time we will definitely get a marble from any of those five colours. Thus getting two marbles of same colour.

Q7) In 55 minutes he can lit 5 candles since burning each candle after 10 minutes + 1 candle lit at the first time so total 6 candles he lit. Now the candle he lit at the starting burn out after 40 minutes and the second candle he lit after 10 minutes is burn out after 40 minutes that is after 50 minutes he lit the first candle. So total four candles are burning after 55 minutes he lit the first candle.

Answer 2

3.ratio of salt water to fresh water...

7:193=7/193

so salt water=7x

fresh water=193x

also

7x+193x=1000

200x=1000

x=5

salt=7x=35

6.let us look at the worst case which occurs when each draw will give us a different colour

let 1st draw:red

2nd draw:blue

3rd draw:white

4th draw:green

5th draw:black

therefore 6th draw should give us a repeated colour

7.in 55 mins he will light 6 candles

1st candle goes in 40 mins

2nd in 50 mins

therefore 6-2=4 candles will be still burning