Question

Tom multiplied a number by 21/2 and got 50 as an answer. However, he should have divided the number by 21/2 to get the correct answer. What is the correct answer?

Answer 1

To correct Tom's error, we divide 50 by the reciprocal of 21/2, which is 2/21. After doing the calculation, we find that the original number is approximately 4.76.

Step-by-step explanation:

Tom initially multiplied a number by 21/2 and received 50 as a result. However, the correct operation was to divide the number by 21/2. To find the original number, we'll use the reciprocal approach.

Tom multiplied the number (let's call it 'x') by 21/2 to get 50:
x * (21/2) = 50
But if we find the reciprocal of 21/2, which is 2/21, we can reverse the multiplication into division to find the original number: x
x = 50 * (2/21).

Now, we calculate:
50 * 2 = 100
100 / 21 is approximately 4.76.
So, Tom's original number, when rounded, is approximately 4.76.