Evaluate `7+ 77+777+......`upto `n`

Find the sum of the sequence 7, 77, 777, 7777, . . . to n terms.

Find the sum of the following series : 0. 7+0. 77+0. 777+...... ton terms

Evaluate 9 + 99 + 999 +……… upto n terms.

Evaluate : 9 + 99 + 999 + ........... upto n terms.

If (1 + 3 + 5 + .... " upto n terms ")/(4 + 7 + 10 + ... " upto n terms") = (20)/(7 " log"_(10)x) and n = log_(10)x + log_(10) x^((1)/(2)) + log_(10) x^((1)/(4)) + log_(10) x^((1)/(8)) + ... + oo , then x is equal to

Find the sum of G.P. : (x+y)/(x-y)+1+(x-y)/(x+y)+ . . . . .. . . . upto n terms.

Evaluate: 542.22 - 56.3 - 6.77

Evaluate sqrt(26) correct upto two place of decimal

Sum to n terms the series : 0.7+0.77 + 0.777+ ....

Find the sum of the series 1+3x+5x^2+7x^3+.......... upto n terms.