Nsw education standards authority Interview Questions, Process, and Tips

C

When none of the digits are repeated:

The hundred’s place can be filled by any of the digits: 2, 3, 5, 6, 7 or 8 except the one which has already been used at the thousand’s place, so it can be filled in 5 ways.

Similarly tens’ place can be filled in 4 ways: only those 4 numbers which have not been use either at hundred’s or thousand’s place.
Unit’s place can be filled in only 3 ways. So, total number of nos. Possible =4×5×4×3= 240

625

If both agree stating the same fact, either both of them speak truth of both speak false.
∴ Probability
=3/5×4/7+2/5×3/7=12/35+6/35=18/35

The correct Answer is 69

Assuming the youngest has X years, so we have
X+(X+3)+(X+6)+(X+9)+(X+12)=50
5X+30=50
5X=20
X=4
The youngest has 4 years

time is inversely proportional to speed.
So if speed taken is 4/5 of usual speed, time taken will be 5/4 of usual time
and the difference between time is 10 min
So,
(5/4)t -t=10 min
usual time,t=40 min
late time=40+10=50 min

Mixture is 1.2 L of A + 2.4L of B which is 3.6L total. 1.2L / 3.6L = 1/3 (0.33)

Alcohol content from
2 l of A (62.5%) : 1.35L
4L of B (87.5%) : 3.50L

Total Acohol content in 6 L : 4.85L or 80.8%

Before Swapping
_ _ _ _ _ _ _ Shilpa ……..Reena _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

After Swapping
_ _ _ _ _ _ _ Reena _ _ _ _ _ Shilpa _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
—————————–>14=17 <——————————-

So total number of girls in that row are 30

4 1 1 4
5 1 1 4
+ 0 1 1 4
———-
9 3 4 2

brother and sister

Correct option is C)
Let be students are consider as child
Let the age of child added later be x years.
average age of 12 children =20 years
∴ Total age of 12 children =20×12=240 years
After one more child is added-
Average of 13 children =20−1=19 years
Average age of 13 children =
13
sum of 12 children+x
​

19=
13
240+x
​

⇒240+x=247
⇒x=247−240=7 years
Hence the age of child added later is 7 years.