Question

What will be the minimum number of weighings required to find the packet with defected chocolates if the defected chocolates weigh 11 grams each?

• A. 1
• B. 2
• C. 3
• D. More than 3

Answer 1

The correct option is A 1

We know that one packet contains chocolates with 11 grams weight each. Let us take 1 chocolate from 1st packet, 2 chocolates from 2nd packet, 3 chocolates from 3rd packet and so on till 10 chocolates from 10th packet. In total we have 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55 chocolates. Ideally the weight should have been 55 $\times$ 10 = 550 grams.
Let us say the electronic balance shows the weight as 555 grams, we can say 5 chocolates are defected and hence 5th packet is the one with defected chocolates. Hence, let us say the nth packet is defected, n = (Weight being shown by the balance - 550). So, only 1 weighing is sufficient.