self Maths Puzzle

derive sum of digits of n terms

Read Solution (Total 2)

self Other Question

In the sequence 1, 22, 333, 4444,... the nth term has n number of n's. Then the sum of the digits of the 87th term is What is the radius of the circum circle of the triangle whose sides are 5, 12 and 13 units respectively?
option
A. 2 units
B. 12 units
C. 6.5 units
D. 6 units
E. 7.5 units