9 - 11

9. A clock showing 6 o'clock takes 30 secs to strike 6 times.How long
will it take to strike 12 at midnight?

5 Intervals to strike 6 takes 30 seconds so time between the
strikes is 6 seconds. So to strike 12 it takes 11 intervals so will
take 11 * 6 = 66 seconds

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10. There are 3 societies A,B,C having some tractors each.
A Gives B and C as many tractors as they already have.
After some days B gives A and C as many tractors as they have.
After some days C gives A and B as many tractors as they have.
Finally each has 24 tractors.what is the original No.of
tractors each had in the beginning

A B C
x y z
x-y-z 2y 2z A gives B and C
2(x-y-z) 2y-(x-y-z)-2z 4z B gives C and A
4(x-y-z) 2(-x+3y-z) 4z - 2(x-y-z) - (-x+3y-z)

so we have eqs
x-y-z = 6
-x+3y-z =12
-x - y + 7z = 24
also x + y + z = 3 * 24 could be used.

x = 39, y = 21, z = 12

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11. A,B,C,D,E related.4 of them made these statements each.
i)C is my son in law's brother.
ii)B is my father's brother.
iii)E is my mother in law.
iv)A is my brother's wife.
who made these statements

E is the Mother in Law.
so she makes statement i)
B is the Son in Law A is his wife, C is his brother
C makes statement iv)
B make statement iii)
D makes statement ii) he/she is the child of C.