Question

1+r/100 =21/20 find the value

Answer 1

$hii.. \\ = > 1 + \frac{r}{100} = \frac{21}{20} \\ \\ = > \frac{100 + r}{ 100} = \frac{21}{20} \\ \\ = > 2100 = 20(100 + r) \\ \\ = > 2100 = 2000 + 20r \\ \\ = > 20r = 2100 - 2000 \\ \\ = > 20r = 100 \\ \\ = > r = \frac{100}{20} = 5 \: \: ans \\ \\ hope \: this \: helps :)$

Answer 2

1 + (r÷100) = 21÷20
(100+r) ÷ 100 = 21÷20

Multiplying 20 on both sides,
((100+r) ÷ 100 )20 = (21÷20)20
(100+r)÷5 = 21
100 + r = 21 x 5 = 105
r = 105 - 100 = 5
Therefore, r = 5

Verification:

1 + 5÷100 = 21÷20
(100+5)/100 = 21÷20
105/100 = 21÷20

Simplify 105 and 100,
21÷20 = 21÷20

LHS = RHS.
Hence proved that r = 5