বিস্তারিত সমাধান

ন্যাভিগেশন মেনু

প্রশ্ন ও অপশন

সমাধান ও ব্যাখ্যা

সম্পর্কিত বিষয়

সম্পর্কিত প্রশ্ন

From 7 boys and 5 girls, 6 are to be selected for admission for a particular course. In how many ways can this be done if there must be exactly 3 girls?

350

1050

120

উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।

ব্যাখ্যা ও সঠিক সমাধান

উত্তর: 350

Ways of selecting 3 girls out of 5 = 5C3 = 10 Number of boys to be selected = 6 - 3 = 3 Ways of selecting 3 boys out of 7 = 7C3 = 35 So, total ways = 10 x 35 = 350

পূর্ববর্তী আগের প্রশ্ন

পরবর্তী সামনের প্রশ্ন

The length of a rectangle is 3 times of its width. If the width of the rectangle is 5 inches, what is the rectangle's area, in square inches?

উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।

বিস্তারিত

উত্তর

সমাধান

Given Width of the rectangle = 5 inches So length = 3 × 5 = 15 inches Area of a rectangle is = 5 × 15 = 75 sq. Inch (ans)

২

the average age of 12 children is 20 years. If the age of one more child is added, the average decreased by 1. What is the age of child added later?

উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।

বিস্তারিত

উত্তর

সমাধান

Average of 12 is 20 Total = 12 × 20 = 240 Let the age of one more is x So, total 240 + x Average of 13 is (240 + x)/13 ATQ (240 + x)/13 = 19 or, 240 + x = 13 × 19 or, 240 + x = 247 ∴ x = 7 (ans)

৩

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?

110

উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।

বিস্তারিত

উত্তর

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)

৪

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:

50%

40%

36%

28%

উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।

বিস্তারিত

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)

৫

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?

12%

উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।

বিস্তারিত

উত্তর

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%

৬

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?

3 months

3.5 months

2.5 months

2 months

উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।

বিস্তারিত

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)

৭

Which fraction is the largest?

9/16

7/10

4/5

5/8

উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।

বিস্তারিত

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।

৮

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?

18%

7.5%

উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।

বিস্তারিত

উত্তর

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)

৯

Reza's average in four tests is 80%. what marks does he need in his fifth test to raise his average to 84%.

96%

94%

84%

100%

উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।

বিস্তারিত

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%

১০

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?

75 mph

55 mph

60 mph

65 mph

উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।

বিস্তারিত

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)

প্রশ্ন সমাধান বিষয়

কোর্স

অনুসন্ধান করুন

বিস্তারিত সমাধান

From 7 boys and 5 girls, 6 are to be selected for admission for a particular course. In how many ways can this be done if there must be exactly 3 girls?

সম্পর্কিত বিষয় সমূহ

সম্পর্কিত অন্যান্য প্রশ্ন

The length of a rectangle is 3 times of its width. If the width of the rectangle is 5 inches, what is the rectangle's area, in square inches?

the average age of 12 children is 20 years. If the age of one more child is added, the average decreased by 1. What is the age of child added later?

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?

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:

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?

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?

Which fraction is the largest?

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?

Reza's average in four tests is 80%. what marks does he need in his fifth test to raise his average to 84%.

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?