What is the unit digit in the product (365 x 659 x 771)?

Unit digit in 34 = 1 Unit digit in (34)16 = 1

Unit digit in 365 = Unit digit in [ (34)16 x 3 ] = (1 x 3) = 3

Unit digit in 659 = 6

Unit digit in 74 Unit digit in (74)17 is 1.

Unit digit in 771 = Unit digit in [(74)17 x 73] = (1 x 3) = 3

Required digit = Unit digit in (3 x 6 x 3) = 4

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The ratio of two brothers John and Harry is 4 / 5 . However if the age of John before 10 years and that of Harry after 10 years than the original ratio is reversed. What is the age of Harry?

let's John age =a and Harry age = b

Given that

a/ b =5 / 4

4 a=5 b

4a- 5b =0..... equation 1

and also given that

a - 10 / b + 10 =4 / 5

a5 - 50= 4b+40

5 a- 4b= 90 .......equation 2

By solving both equation

so, Harry is 40 years old.

A family consists of 6 member P, Q, R, X, Y and Z . Q is a son of R but R is not mother of Q. P and R a married couple. Y is the brother of R. X is a daughter of P. Z is a brother of P. Who is the brother in law of P?

Q is son of R but R is not a mother. So, R is the father of Q. P is married to R. So, P is the wife of R and the mother of Q . X is a daughter of P and hence, of R and so she is a sister of Q. Y is a brother of R and Z is a brother of P. R is husband of P and Z brother of P.

R is the husband of P and Z is a brother of P. R is husband of P and Y is brother of R so, Y is brother in law of P.

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In following questions, one term in number series is incorrect.

Find out the incorrect number

445, 221, 109, 46, 25, 11, 4

Find out the incorrect number

445, 221, 109, 46, 25, 11, 4

3 is subtracted from each number and the result is divided by 2 to obtain the next number of the series.

So , 46 is wrong and must be replaced by 109 - 3 / 2 i.e. 53..