A can complete a work in 80 days A works at it for 10 days and then B alone finishes the remaining work in 42 days in how many days A and B do it together
Answers
Answer:
30 days
Step-by-step explanation:
A's 1 days' work =
80
1
A's 10 days' work =
80
10
=
8
1
Remaining work =1−
8
1
=
8
7
8
7
of the work is completed by B in 42 days
∴ The whole work is completed by B in
7
42×8
days = 48 days
∴ B's 1 days' work =
48
1
(A + B)'s 1 days' work =
80
1
+
48
1
=
240
3+5
=
240
8
=
30
1
∴ A and B can complete the whole work together in 30 days
Step-by-step explanation:
Calculations of A worker:
Time taken by A to complete the whole work = 80 days.
Amount of work done by A in 1 day = 180" role="presentation" style="margin: 0px; padding: 0px; display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 15px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">180180
Amount of work done by A in 10 days = 1080=18" role="presentation" style="margin: 0px; padding: 0px; display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 15px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">1080=181080=18
Amount of work left for B = 1−18=78" role="presentation" style="margin: 0px; padding: 0px; display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 15px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">1−18=781−18=78
Calculations for B worker:
Time taken by B to complete 7/8th of the work = 42 days
Time taken by B to complete the whole work = 42×87=48" role="presentation" style="margin: 0px; padding: 0px; display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 15px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">42×87=4842×87=48 days.
Amount of work completed by B in 1 day = 148" role="presentation" style="margin: 0px; padding: 0px; display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 15px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">148148
Calculation for time taken by A + B
= 1148+180" role="presentation" style="margin: 0px; padding: 0px; display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 15px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">1148+1801148+180
=15240+3240" role="presentation" style="margin: 0px; padding: 0px; display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 15px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">=15240+3240=15240+3240
=18240" role="presentation" style="margin: 0px; padding: 0px; display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 15px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">=18240=18240
=2408=30" role="presentation" style="margin: 0px; padding: 0px; display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 15px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">=2408=30=2408=30
Thus they will take 30 days to complete the work.