Question

Rekha is saving money to buy gift for herself on her birthday. She puts Rs. 2.50 in her piggy bank on the first day. Each day after that she puts Rs. 1.50 more than what she had put on the previous day. How much will she put on the fifth day?

Answer 1

Step-by-step explanation:

$\bf{\underline{\underline\red{Given:-}}}$

• Rekha puts Rs. 2.50 in her piggy bank on her first day.

• Each day after that she puts Rs. 1.50 more than what she had put on the previous day.

$\bf{\underline{\underline\blue{To\:Find:-}}}$

• How much money she puts on the fifth day.

$\bf{\underline{\underline\green{Solution:-}}}$

$\tt Concept \: used : Arithmetic \: progression$

The money she put in the first day = Rs. 2.50

As she puts Rs. 1.50 more than the previous day

The money she put in the second day

= 2.50 + 1.50

= Rs. 4

Common difference = 1.50

As we know that

The nth term of an A.P is given by the formula:-

$\boxed{ \rm \leadsto a_{n} = a + (n - 1)d}$

• a = first term = 2.50

• d = common difference = 1.50

• As we need to find the money she puts on the fifth day so ; n = 5

Therefore:-

${ \rm \implies a_{5} = a + (5- 1)d}$

${ \rm \implies a + 4d}$

${ \rm \implies 2.50 + 4(1.50)}$

${ \rm \implies 2.50 + 6}$

${ \rm \implies 8.50}$

Therefore:-

$\boxed{ \rm She \: puts \: Rs. \: 8.50 \: on \: the \: fifth \: day}$