Time and Work
MCQs Math


Question:     Brandon can finish a work in 83 days. Samuel can finish the same work in 88 days while Gregory can finish the work in 93 days. How long will it take to finish it if they work together?


Correct Answer  29 6269/23207 days or 29.27 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Brandon = 83 days

And, the number of days required to finish the same work by Samuel = 88 days

And, the number of days required to finish the same work by Gregory = 93 days

Thus, the number of days required to finish the work by all of them if they work together = ?

Here,

∵ In 83 days the work is done by Brandon = 1

∴ The work done by Brandon in 1 day = 1/83

Similarly,

∵ In 88 days the work is done by Samuel = 1

∴ The work done by Samuel in 1 day = 1/88

Similarly,

∵ In 93 days the work is done by Gregory = 1

∴ The work done by Gregory in 1 day = 1/93 part

Now, the work done by Brandon, Samuel, and Gregory together in 1 day

= Brandon's 1 day work + Samuel's 1 day work + Gregory's 1 day work

= 1/83 + 1/88 + 1/93

= 8184 + 7719 + 7304/679272

= 23207/679272 part of work

This means in 1 day, 23207/679272 part of work is done by Brandon, Samuel and Gregory working together.

Now, the number of days required to finish 23207/679272 part of work by Brandon, Samuel, and Gregory working together = 1

∴ the number of days required to finish the whole work (1 work) by Brandon + Samuel + Gregory together

= 1/23207/679272

= 1 × 679272/23207 = 679272/23207 days

= 29 6269/23207 days = or 29.27 days

Thus, Brandon, Samuel, and Gregory working together will finish the total work (1 work) in 29 6269/23207 days = or 29.27 days Answer

Shortcut Trick to solve the problems based on time and work using formula

Case: If A can finish a work in a days, B can finish the same work in b days, and C can finish the work in c days
then working together the number of days required to finish the work
= a × b × c/ab + ac + bc days.

Here given,

The number of days required to finish the work by Brandon = 83 days

And the number of days required to finish the same work by Samuel = 88 days

And the number of days required to finish the work by Gregory = 93 days

Thus, the number of days required to finish the work by Brandon, Samuel, and Gregory together = ?

Here a = 83 days

And, b = 88 days

And, c = 93 days

Thus, using formula a × b × c/ab + ac + bc days

The number of days required to finish the work when Brandon, Samuel, and Gregory working together

= 83 × 88 × 93/83 × 88 + 83 × 93 + 88 × 93 days

= 679272/7304 + 7719 + 8184 days

= 679272/23207 days

= 679272/23207 days

= 29 6269/23207 days or 29.27

Thus, Brandon, Samuel, and Gregory together will finish the work in 29 6269/23207 days or 29.27 days Answer


Similar Questions

(1) If David can finish the work in 10 days and Christopher can finish the same work in 13 days, then in how many days both can finish the work together?

(2) If Carol can finish the work in 46 days and Alexander can finish the same work in 51 days, then in how many days both can finish the work together?

(3) If Patrick can finish the work in 95 days and Vincent can finish the same work in 100 days, then in how many days both can finish the work together?

(4) If Steven can finish the work in 37 days and Jonathan can finish the same work in 42 days, then in how many days both can finish the work together?

(5) If Thomas can finish the work in 18 days and Andrew can finish the same work in 21 days, then in how many days both can finish the work together?

(6) If Donna can finish the work in 39 days and Brandon can finish the same work in 42 days, then in how many days both can finish the work together?

(7) Patrick can finish a work in 95 days. Jack can finish the same work in 100 days while Dennis can finish the work in 105 days. How long will it take to finish it if they work together?

(8) If Larry can finish the work in 77 days and Lawrence can finish the same work in 82 days, then in how many days both can finish the work together?

(9) If Elizabeth can finish the work in 14 days and Daniel can finish the same work in 19 days, then in how many days both can finish the work together?

(10) Nicholas can finish a work in 69 days. Jonathan can finish the same work in 74 days while Stephen can finish the work in 79 days. How long will it take to finish it if they work together?


NCERT Solution and CBSE Notes for class twelve, eleventh, tenth, ninth, seventh, sixth, fifth, fourth and General Math for competitive Exams. ©