২৩৩১১
Four years ago, the father's age was three times the age of his son. The total of the ages of the father and the son after four years, will be 64 years. What is the father's age at present?
উত্তর
None of these
সমাধান
Hints: ধরি, পিতার বর্তমান বয়স. F son এর S 4 বছর আগে
F - 4 = 3(s - 4)
F - 4 = 3S - 12
4 বছর পরে, F + 4 + s + 4 = 64
s = 64 - 8 - F = 56 - F
F - 4 = 3(56 - F) - 12
F - 4 = 168 - 3F - 12
4F = 168 - 12 + 4 = 160
F = 60
সঠিক উত্তর নাই
২৩৩১২
If the length of rectangle A is one-half the length of rectangle B, and the width of rectangle A is one-helf the width of rectangle B, what is the ratio of the area of rectangle A to the are of rectangle B?
উত্তর
1/4
সমাধান
Hints: rectarged B এর length l হলে A এর length = 1/2 l
rectarged B length W এর width = 1/2 w
ratio আয়তন = A/B = 1/2l × 1/2 w / l × w = 1/4
২৩৩১৩
A starts business with Tk. 3500 and after 5 months, B joins with A as his partner. After a year, the profit is divided in the ratio 2: 3. What is B's contribution in the capital?
উত্তর
Tk. 9000
সমাধান
Hints: ধরি, B এর মূলধন হয়ছে,
3500 × 12/ 7 × x = 2/3
14x = 126000
x = 9000
২৩৩১৪
A sum of money is to be distributed among A, B, C, D in the proportion of 5: 2: 4: 3. If C gets Tk. 1000 more than D, what is B's share?"
উত্তর
Tk. 2000
সমাধান
Hints: ধরি, তাদের share যথাক্রমে 5x, 2x, 4x, 3x
তাহলে, 4x - 3x = 1000
B এর share = 2x = 2 × 1000 = 2000
২৩৩১৫
If x = 2y =3z and xyz =36 , what is the value of z?
উত্তর
root 2
সমাধান
x = 2y = 3z∴ x = 3z;y = 3z/2So, xyz = 36⇒ 3z.3z/2.z = 36⇒ 9z³ = 72⇒ z³ = 8⇒ z³ = 2³∴z = 2
২৩৩১৬
A ferry, when empty , travels twice as fast as when it is full. It travels 20 miles south with a cargo, spends 30 minutes for unloading , and returns to its original port empty in a total of 8 hours , what is the speed of the ferry when it is empty?
উত্তর
8 mph
সমাধান
Let, In 1 hours the ferry goes x km when loaded
and " 1 " " " " 2x " " empty
According to question,
20x + 202x = 8 - 0·5 hours ∴30 minute = 12hours = 0·5hours⇒40 + 202x = 7·5⇒60 = 15x∴x = 4So, ferry goes2×4 = 8 km in 1 hours when it is empty.
২৩৩১৭
A bicycle has two wheels of 120 cm and 40 cm in diameters. when the large wheel makes 10 revolutions , how many revolutions does the small wheel make in that time?
উত্তর
30%
সমাধান
The circumference of big wheel = 120π and small wheel = 40π∴ big wheel is 3 times largers.
So, small circle will make 3×10 = 30 revolutions.
২৩৩১৮
Baki lives 2 miles west of Raju's house. Rafiq lives 3 miles of Raju's house and 2 miles west o Diba's house. what is the straight-line distance from Baki's house to Diba's house?
উত্তর
5 miles
সমাধান
So, 2 + 22 + 32 = ad2⇒ad2 = 16 + 9⇒ad = 25∴ad = 5
২৩৩১৯
On Tuesday, 30 of the students in a class took a test and their average score was 83.5. On Thursday , the other 5 students took the test, and their average score was 94. what was the average for the entire class?
উত্তর
85%
সমাধান
Average = 30×83·5 + 5×9430 + 5 = 2505 + 47035 = 85 = 85%
২৩৩২০
If the average of 7 , 13 , p , and q is 17 , what is the average of ( p +1) and (q -9)?
উত্তর
25
সমাধান
Average, 7 + 13 + p + q4 = 17Or, 20 + p + q = 68⇒p + q = 68 - 20∴p + q = 48
Again, average p + 11 + q + 92 = p + q + 22 = 48 + 22 = 25