Question

Nilofer is finding the sum of 13.24and 4.35 using a calculator

She has entered one of the digits of 13.24 incorrectly.

The answer she gets is 0.4 more than the correct answer she would have obtained otherwise

Which of the digits of 13.24 has she entered incorrectly?

A) 1
B) 2
C) 3
D) 4

Answer 1

the incorrect answer that he got was: 13.24+4.35=17.59
the correct answer was : 17.59-0.4 =17.55
then the digit 4 must be incorrectly entered.

Answer 2

We need to recall the basic rules of addition and subtraction.

Given:

Nilofer is finding the sum of $13.24$ and $4.35$.

She has entered one of the digits of the number $13.24$ incorrectly.

The answer she gets is $0.4$ more than the correct answer.

The correct sum is : $13.24+4.35=17.59$

The answer Nilofer got is,

$17.59+0.4=17.99$

The incorrect number entered by Nilofer is,

$17.99-4.35=13.54$

Nilofer entered $5$ instead off $2$.

Hence, the correct option is B) $2$ .