Question

a can do a work in 10 days and b can do it in 15 days. They work together for a few days and a completed the rest of the work in five days. Find the number of days they worked together

Answer 1

Answer:

for 3 days they work together

Step-by-step explanation:

Given :- A complete work in 10 days

B can do this work in 15 days

To find out => find no. of days they work toghter when A does the work in last days

Solution :-

A = 10 days

B = 15 days

(let total work is 30 unit - by lcm)

if total work is 30 unit and a can do this work in 10 days then efficiency will be => 30/10 = 3 unit per day

=> similarly B = 30/15 = 2 unit per day

Also we know that a completed rest of work in 5 days which means => 5×3 = 15 unit

it means A complete the remaining 15 unit so fist 15 unit work they complete toghter so

=>15/3+5

=> 3

for 3 days they work toghter

total time taken = 3+5 = 8 days