বিগত সালের প্রশ্ন ও প্রশ্ন ব্যাংক
বিসিএস, ব্যাংক, প্রাথমিক শিক্ষক ও সকল সরকারি চাকরির বিগত সালের প্রশ্ন ও অধ্যায়ভিত্তিক নির্ভুল সমাধান
Solution:
Given the numbers 14, 18, 21, 28
First, factorize the numbers,
14 = 2 × 7
18 = 2 × 3 × 3
21 = 3 × 7
28 = 2 × 2 × 7
∴ LCM is = 2 × 2 × 3 × 3 × 7 = 252
So the number will be = 252/2 = 126
The least number is 126
Solution:
Let, greater number be = x.
Smaller number = 150 - x
ATQ,
(40 × x)/100 = {60(150 - x)}/100
⇒ 40x/100 = (9000 - 60x)/100
⇒ 100x = 9000
⇒ x = 9000/100
∴ x = 90
Solution:
Here, the first divisor (91) is a multiple of the second divisor (13).
∴ Required remainder = Remainder obtained on dividing 17 by 13
⇒ 17 = ( 13 × 1 ) + 4
∴ Hence Required remainder = 4
Solution:
Let, the number be = x.
ATQ,
(x + 12)/6 = 112
⇒ x + 12 = 672
⇒ x = 672 - 12
⇒ x = 660
So, Correct answer = (660/6) +12
= 110 + 12 = 122
Solution:
Let the two integers be x and y
The difference between the two integers is 6,
∴ x - y = 6 and their product is, xy = 352
Now, We know
∴ x + y = 38
∴ The sum of the two numbers is 38.
Solution:
Let the three numbers are 2x, 5x, and 8x, where x is a constant multiplier.
The average of the three numbers is given as 75.
The average of the three numbers is,
⇒ (2x + 5x + 8x)/3 = 75
⇒ 15x/3 = 75
⇒ 5x = 75
⇒ x = 75/5
∴ x = 15
The first number is = 2x = 2 × 15 =30
The third number is = 8x = 8 × 15 = 120
∴ The difference between the larger and smaller numbers is, 120 − 30 = 90
Solution:
let, the number = x
According to the question,
⇒ x - 15 = 25% of x
⇒ x - 15 = 25x/100
⇒ x - 15 = x/4
⇒ 4x - 60 = x
⇒ 4x - x = 60
⇒ 3x = 60
⇒ x = 60/3
∴ x = 20
So, the larger number is 20.