২২৭৭১
A man donated 5% of his income to a charitable organization and deposited 20% of the remainder in a bank. if he now has Tk. 1919 left, then his income is:
উত্তর
Tk 2525
সমাধান
Let total income is x
5% for Charitable organisation is 5% of x = 5x/100 = 0.05 x
Balance available ( x - 0.05x) = 0.95x
20% deposited in bank = 20% of 0.095x
= (20 × 0.95x)/100
= .19 x
Now left ( 0.95x - 0.19x) = 0.76x
ATQ,
0.76x = 1919
x = 1919/ 0.76
x = 2525 (ans)
২২৭৭২
A woman had 50 ducks. All but 8 died. How many ducks are still alive?
উত্তর
8
সমাধান
All but 8 মানে ৮টি বাদে বাকি সব।
২২৭৭৩
An ambulance travels 10 miles at a speed of 50 miles per hour. how fast must the ambulance travel on the return trip if the round trip travel time is 20 minutes?
উত্তর
75 mph
সমাধান
Given, Distance = 10 miles, speed = 50 miles per hour
Time taken = distance ÷ speed
= 10÷ 50 = 1/5 hour = 1/5×60 = 12 mins
Total time = 20 mins
Time for returned trip = 20 - 12 = 8 min
8 mins = 8/60 = 2/15 hours
Speed = distance ÷ time
= 10 ÷ 2/15
= 10 × 15/2
= 150/2
= 75 mph (ans)
২২৭৭৪
Reza's average in four tests is 80%. what marks does he need in his fifth test to raise his average to 84%.
উত্তর
100%
সমাধান
ধরি, প্রথম 4টি exam এর যোগফল x
এবং 5th exam এ পাওয়া marks y xy = 80x = 4x80and,x + y5 = 84So,Y = 5x84 - x অথাৎ 100%
২২৭৭৫
The sum of principal and simple interest of a certain amount of money would be Tk. 460 after three years from now and Tk. 500 after five years from now. What is the related interest rate?
উত্তর
5%
সমাধান
(5 - 3) = 2 years interest = (500 - 460) = 40 tk
1 years interest = 40/2 = 20 tk
3 year's interest 20 × 3 = 60 tk
Principle amount = (460 - 60) = 400 tk
Interest rate = (60×100)/(400×3) = 5% (ans)
২২৭৭৬
Which fraction is the largest?
উত্তর
4/5
সমাধান
Generally উপরে নিচের Difference যত less হয় fraction তত large । তবে পার্থক্য একই হলে, যে ক্ষেত্রে ব্যবহৃত সংখ্যা বড় সেই fraction বড়। যেমন 4/5 ও 9/10 এর মধ্যে 9/10>4/5।
২২৭৭৭
Humayra borrowed Tk. 240, free of interest, to pay for her new hair band. If she pays back 20% of the amount each month and has already paid back Tk. 120. how many months have passed since she took the loan?
উত্তর
2.5 months
সমাধান
As She pays 20% of the amount each month
So, 20% of 240
= 20/100 × 240
= 48 tk
She paid back 120 tk
So, remaining (240 - 120) = 120
48 tk pays back in 1 month
So, 120 tk pays back in 120/48 = 2.5 months (ans)
২২৭৭৮
The owner of Aarong starts to calculate the percentage of customers who purchase Tagas. if 40% of the total customers who visit the store actually purchase goods and 15% of them purchase tagas, then what percentage of Aarong's customers are Taga buyers?
উত্তর
6%
সমাধান
Let the total Customers number = 100
Then Customers who actually purchase goods = 40
And Customers who purchase tagas = 40 × 15/100 = 6
Required percentage = 6%
২২৭৭৯
The price of desktop computer is discounted by 20%, and reduced price is then discounted by 20%. The series of successive discount is equivalent to a single discount of:
উত্তর
36%
সমাধান
Let the price of desktop computer be 100
Then after first discount price becomes 80
Then again it is discounted by 20%
So the Price Becomes = 80 (80 × 20/100) = 64
So a single discount will be = (100 64) = 36%. (ans)
২২৭৮০
Of the 120 households in an area, 55 have cars, 35 have motor bikes, and 20 have both cars and motor bikes. How many of the households in the area have neither cares nor motor bikes?
উত্তর
50
সমাধান
Given total = 120, n(C) = 55, n( B) = 35 and n (C U B) = 20,
none = ?
Total = n(c) + n(B) n(CUB) + none
120 = 55 + 35 - 20 + none
None = 50 (ans)