Question

A can do a work in 8 days and B in 12 days. They work together for 3 days. What part of the work is left?

• A. 1/4
• B. 5/8
• C. 3/8
• D. 7/24

Answer 1

Answer:

C. 3/8

Let's calculate their combined work rate.

Step 1: Individual work rates

• A completes the work in 8 days → rate = $(\frac{1}{8})$ per day

• B completes the work in 12 days → rate = $(\frac{1}{12})$ per day

Step 2: Combined rate

$\frac{1}{8}+\frac{1}{12}$
$=\frac{3}{24}+\frac{2}{24}$
$=\frac{5}{24}$

Together, they complete $(\frac{5}{24})$of the work per day.

Step 3: Work done in 3 days

$3 \times \frac{5}{24}$
$=\frac{15}{24}$
$=\frac{5}{8}$

Step 4: Work left

$1-\frac{5}{8}$
$=\frac{3}{8}$

Answer:$(\frac{3}{8})$ of the work is left.