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Grade 12th passMagical Mathematics[Interesting Approach]

A repunit is a number that contains only the digit 1, and the repunit of n digits is denoted by

r(n)= 11111...1111 there are total n1

If f(x)=

90x2+20x2+1

then find the sum of digits of the number f(r(10))

Profile image of gdbusher
11 Years agoGrade 12th pass
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4 Answers

Profile image of Gman Namg
ApprovedApproved Tutor Answer11 Years ago
i think 21
 
Profile image of Gman Namg
11 Years ago
21
Profile image of grenade
ApprovedApproved Tutor Answer11 Years ago
it will be 21
Profile image of ng29
ApprovedApproved Tutor Answer11 Years ago
ANSWER WILL BE 21