Question

A can do a piece of work in x days and B
can do the same work in (x + 16) days. If both
working together can do it in 15 days:
calculate X'.​

Answer 1

Answer:

A can do in 1 days is 1/x part

B can do in 1 day is 1/(x+16) part

so, A+B together can do in 1 day

{1/x+1/(x+16)} part

=(x+16+x)/x(x+16) part

=(2x+16)/x(x+16)part

so,both working together can do it in

x(x+16)/((2x+16)

according to question,

x(x+16)/(2x+16)=15

=> x^2+16x=15(2x+16)

=> x^2+16x=30x+240

=> x^2+16x-30x-240=0

=> x^2-14x-240=0

=> x^2-24x+10x-240=0

=> x(x-24)+10(x-24)=0

=> (x-24)(x+10)=0

=> x-24=0

=> x=24

x+10=0

=> x= -10

x can not be negative

so x=24