Question

Simple interest on an amount at 4% per annum for 13 months is more than the simple interest on the same sum for 8 months at 6% per annum by rs 40. what is the principal amount

Moderator please answer it's urgent​

Answer 1

Explanation:

Interest for 13 months at 4%

Interest per year = 4%

interest per month = 4 ÷ 12 = 1/3 %

Interest for 13 months = 1/3 x 13 = 13/3 %

Interest for 8 months at 6%:

interest per year = 6%

interest per month = 6 ÷ 12 = 0.5%

interest for 8 months = 0.5 x 8 = 4%

Define x:

Let the principal amount be x

Solve x:

13/3% of x - 4% of x = 40

1/3 % of x = 40

1% of x = 120

100% of x = 120 x 100 = Rs 12000

Answer: (b) Rs 12000

Answer 2

Answer:

${Questions↓}$

Simple interest on an amount at 4% per annum for 13 months is more than the simple interest on the same sum for 8 months at 6% per annum by rs 40. what is the principal amount

${Answer↓}$

${We\: have \:to \:find \:the \:principal \:amount.}$

${Interest\: for\: 13\: months\: at \:4%}$

${→Interest \:per\: year = 4\: %}$

${→Interest\:\: for\: 13 \:months = 1/3 x 13 = 13/3 %}$

$\bf{Interest \:for\: 8 months \:at\: 6%:}$

${interest\: per \:year\: = 6 \:%}$

${interest \:per \:month = 6 ÷ 12 = 0.5 %}$

${interest \:for\: 8 \:months = 0.5 x 8 = 4 %}$

$\bf{Let \:the \:principal\: amount\: be\: x}$

${13/3% \:of \:x – 4% \:of \:x = 40}$

${1% of x = 120}$

${100% of x = 120 x 100 = Rs 12000}$