বিসিএস, ব্যাংক, প্রাথমিক শিক্ষক ও সকল সরকারি চাকরির বিগত সালের প্রশ্ন ও অধ্যায়ভিত্তিক নির্ভুল সমাধান
A tap can fill a tank in 6 hours.
A tap can fill half of a tank in 6/2 or 3 hours.
4 tap can fill half of a tank in 3/4 hours = 45 min
Total time taken = 3 hours 45 min
প্রশ্নমতে, : 1/8 - 1/x = 1/10
1/x = 1/8 - 1/10
1/x = (5 - 4) / 40
1/x = 1/40
x = 40
∴ x = 40 hours
Expression:
1 / (1/p + 1/q - 1/r)
1 / (1/p + 1/q - 1/r) = 1 / ( (qr + pr - pq) / pqr )
1 / ( (qr + pr - pq) / pqr ) = pqr / (qr + pr - pq)
∴ The simplified expression is: pqr / (qr + pr - pq)
Given:
Time taken by both pipes together = (24 × 72) / (24 + 72)
Time taken by both pipes together = 1728 / 96 = 18 hours
∴ Time taken by both pipes to fill the tank is: 18 hours
Given:
The rates of filling by each pipe are:
ATQ,
1/x + 2/x + 4/x = 1/5
7/x = 1/5
x = 35 hours
∴ The time taken by Pipe A alone to fill the tank is: 35 hours
Given:
Compound Amount Formula:
Compound Amount = P × (1 + r)^n
Substitute the given values:
Compound Amount = 600 × (1 + 1/10)^2
Compound Amount = 600 × (11/10)^2
Compound Amount = 600 × (11/10) × (11/10) = 726
∴ Compound Amount = Tk. 726
প্রদত্ত:
আমরা জানি:
I = P × n × r
⇒ I = 800 × (9/12) × 0.125
⇒ I = 800 × 0.75 × 0.125 = 75
∴ সুদ: Tk. 75
Given:
Step 1: Remaining amount
Remaining = 10,000 - (2,000 + 4,000 + 1,400) = Tk. 2,600
Step 2: Interest from first three parts
Total known interest = 160 + 300 + 119 = Tk. 579
Step 3: Total required interest (average 8.13%)
Total interest = 10000 × 8.13% = Tk. 813
So, interest needed from remaining = 813 - 579 = Tk. 234
Step 4: Find rate on remaining Tk. 2,600
(2600 × r) / 100 = 234
⇒ 26r = 234
⇒ r = 234 / 26 = 9%
∴ Required rate of interest = 9%
Solution:
Here,
P = M
r = M%
I = M
n = 4
We know that,
I = Pnr
M = M × 4 × (M/100)
⇒ 1 = M/25
∴ M = 25
