Question

A certain sum of money triples itself in 5 years at si. In how many years it will be five times ?
1. 10
2. 11
3. 13
4. 12

Answer 1

Correct Answer - Option 1 : 10

Given

A certain sum of money triples itself in 5 years at si

Concept used

Si = P × R × T / 100

Calculation 

Let the principal be P 

Principle becomes three times 

⇒ \(\frac{{{n_1} - 1}}{{{n_2} - 1}} = \frac{{{r_1}{t_1}}}{{{r_2}{t_2}}}\)

⇒ \(\frac{{3 - 1}}{{5 - 1}} = \frac{5}{{t{}_2}}\)

⇒ \(\frac{1}{2} = \frac{5}{{t{}_2}}\)

t₂ = 10 years