Question
Riya completes 40% of a task in 24 days, while Siya
finishes 30% of the same task in 27 days. Riya begins the task alone and stops after 30 days. How long will Siya take to finish the rest?Solution
ATQ,
Time taken by Riya to complete whole work = (24 / 0.40) = 60 days
Time taken by Siya to complete whole work = (27 / 0.30) = 90 days
Let total work = LCM of 60 and 90 = 180 units
Efficiency of Riya = 180 / 60 = 3 units/day
Efficiency of Siya = 180 / 90 = 2 units/day
Work done by Riya in 30 days = 30 × 3 = 90 units
Remaining work = 180 - 90 = 90 units
Time taken by Siya = 90 / 2 = 45 days

What value should come in the place of (?) in the following questions?
?2 = 240 * √25 + 38 * 5 - 94
? = 6.25% of 240 + 25 2 + 17 2 – 16 × 17
(-251 × 21 × -12) ÷ ? = 158.13
What will come in the place of question mark (?) in the given expression?
(252 + 198) ÷ ? + 126 ÷ 3 = 144 ÷ 2
Simplify the following questions:
(11) 8.5 × (121) 5.5 ÷ (1331) 5.5 = (11) ? Â
...24% of 15% of 500 + 122 = ?2 – (232 ÷ 2)
 Solve: 666/6/3 = ?
139 + 323 – √169 + ? = 450
What will come in the place of question mark (?) in the given expression?
(50 × 6 ÷ 12) × 9 = ?