Question

5. 'A' and 'B' together can paint the wall in 10 days, 'B' and 'C' can paint the wall in 12
days, while 'A' and 'C' can d it in 15 days. If A, B & C work together then they can
finish the work in
days.

Answer 1

${\boxed{\mathtt{\green{Answer}}}}$

A , B and C all together can finish the work in 8 days.

${\boxed{\mathtt{\green{GIVEN}}}}$

➾ A and and B can finish the work in 10 days.

➾ B and C can finish the same work in 12 days.

➾ Whereas A and C can finish it in 15 days.

${\boxed{\mathtt{\green{To\: Find}}}}$

➾ In how many days these three can together finish the work .

${\boxed{\mathtt{\green{Solution}}}}$

Complete work can be done in.

➾ A + B = 10 days .

➾ B + C = 12 days .

➾ C + A = 15 days .

In one day how much part of work is done .

$A \: + \: B \: = \: \frac{1}{10} th \: part$

$B \: + \: C \: = \: \frac{1}{12}th \: part \:$

$A \: + \: C \: = \: \frac{1}{15} th \: part$

On adding these three :-

$2( \: A \: + \: B \: + \: C \: ) \: = \: \frac{1}{10} \: + \: \frac{1}{12} \: + \: \frac{1}{15}$

$= \: \frac{6 + 5 + 4}{60}$

$= \frac{15}{60}$

$= \frac{1}{4 \times 2} \: th \: part$

$= \: \frac{1}{8} \: th \: part$

So , in one day A , B , C can can finish 1 / 8 th part of their work.

It means they can finish there entire work in 8 days .

${\boxed{\mathtt{\red{\: 8 \: days \: is \: the \: Answer}}}}$

Answer 2

$\large \underline{ \red{ \boxed{ \bf \pink{Answer}}}}$