Question
Three workers, A, B, and C, can complete a task in 40
days, 72 days, and 45 days respectively. They start working together, but A leaves 20 days before the work is completed, and C continues working for 5 more days after A leaves. How many days does it take to complete the whole work?Solution
Let, total amount of work = 360 units (LCM of 40, 72 and 45) Efficiency of βAβ = 360/40 = 9 units/day Efficiency of βBβ = 360/72 = 5 units/day Efficiency of βCβ = 360/45 = 8 units/day Let, the whole work is completed in βxβ days So, βAβ worked for βx β 20β days And, βCβ worked for x β 20 + 5 = βx β 15β days So, 9(x β 20) + 8(x β 15) + 5 Γ x = 360 Or, 22x = 660 Or, x = 30
Evaluate:
β729 + β49 - β16 + 1/β64
Simplify:

(1/5)(40% of 800 β 120) = ? Γ 5
2/5 of 3/4 of 7/9 of 7200 = ?
`sqrt(5476)` + 40% of 1640 = ? `xx` 4 - 2020
? = (22% of 25% of 60% of 3000) + 21
Determine the simplified value of the given mathematical expression.
(342 β 20% of 5280) = ? Γ· 3
β157464 =?