Question

If 5 examiners can examine a certain number of answer books in 6 days by working 4 hours a day for how many
hours a day would 6 examiners have to work in order to examine thrice the number of answer books in 10 days?​

Answer 1

Answer: 6 hrs a day

Step-by-step explanation:

We will solve the question by using the following formula:

[M1 * H1 * D1] / W1 = [M2 * H2 * D2] / W2 …… (i)

Here,

M1 = no. of examiners = 5

H1 = no. of hours = 4 hrs a day

D1 = no. of days = 6 days

M2 = 6

D2 = 10 days

H2 = need to find?

Also, given that  

6 examiners have to examine thrice the no. of books than 5 examiners

∴ W2 = 3 W1 …… [W1 & W2 are the no. of work done by the 5 & 6 examiners respectively]

⇒ W2 / W1 = 3 / 1

Therefore,  

Substituting the values in the formula (i), we get

[5 * 4 * 6] / 1 = [6 * H2 * 10] / 3

⇒ H2 = [5 * 4 * 6 * 3] / [6 * 10] = 6 hrs a day

Thus, 6 examiners have to work 6 hrs a day, in order to examine thrice the number of answer books in 10 days.