Question

Four children measure the length of a table which was about 2m. Each of them used different ways to measure it. Which one of them would get the most accurate length? Give a reason for your answer.

• A. Sam measured it with a half meter long thread
• B. With a 15cm scale from her geometry box
• C. Reena measured it using her hand span.
• D. Salim measured it using a 5m long measuring tape.

Answer 1

The correct option is D

Salim measured it using a 5m long measuring tape.

The explanation for the correct answer

In the case of option D,

1. Salim took measurements with a $5m$ measuring tape. With the 5m tape, he could easily measure the table in one shot. Because tape is a standard length measuring equipment, the measurement will be more precise than those obtained by others.
2. As a result, we can say that Salim will take the most precise measurements.
3. Salim's measurement was the most precise since he utilized a standard measuring tool that could measure the length in one go.

The explanation for the incorrect answer

In the case of option A,

1. Sam used a half-meter-long thread to measure the table.
2. He has to measure the $2m$ long table four times using a half-meter-long thread. He won't be able to measure the table all at once.
3. Furthermore, there are no measurement markings on the thread. The thread cannot be used as a standard measurement device.
4. As a result, there's a potential that Sam's measurements are incorrect.

In the case of option B,

1. Gurmeet used a $15cm$ scale to determine his height.
2. In comparison to the $2m$ long table, $15cm$ is small. Gurmeet is unable to measure the table in one sitting.
3. The chances of errors in measurement are very high in the case of Gurmeet.

In the case of option C,

1. Reena used the length of her hand to gauge the distance.
2. A hand's length cannot be used as a standard measurement tool. The length of a person's hand varies from person to person. The span of a hand does not have a set length.
3. As a result, Reena's measurements are also off.

Hence, option D is the correct answer.