A 5-digit number \overline{abcde} , when multiplied by 9, gives the 5-digit number \overline{edcba} . The sum of the digits in the number is

KVPY 2020-21 SA Exam Previous Papers

Question : 15 of 80

Marks: +1, -0

A 5-digit number

\ov{abcde}

, when multiplied by 9, gives the 5-digit number

\ov{edcba}

. The sum of the digits in the number is

Solution:

abcde × 9 = abcde (10 -1)

= abcde0-0abcde=0edcba

(a-1)-0=0 \⇒[a=1]

10-e=a \⇒[e=9]

b-a=e \⇒[b=0]

(e-1)-d=b \⇒[d=8]

d-c=c \⇒[c=4]

\ov {a b c d e}=10989

sum of digits

=27

Go to Question:

Prev Question

Next Question