Number System - Study Mode

[#256] If sum of the two number is 80 and ratio is 3 : 5, then find numbers :
Correct Answer

(D) 30, 50

Explanation

Solution: Let number are a, b = 3x, 5x So, 3x + 5x = 8x = 80 x = 10 So, number is : 3 × 10 = 30 5 × 10 = 50

[#257] $$frac{2}{3}$$ of three-fourth of a number is :
Correct Answer

(A) $$frac{1}{2}$$ of the number

Explanation

Solution: $$eqalign{
& = frac{2}{3} imes frac{3}{4} imes n,,,left( {{ ext{n}},{ ext{is}},{ ext{a}},{ ext{number}}}
ight) cr
& = frac{1}{2}n cr} $$

[#258] The greatest four digit number which is exactly divisible by each one of the numbers 12, 18, 21 and 28 :
Correct Answer

(A) 9828

Explanation

Solution: L.C.M of 12, 18, 21, 28 = 252 9999 is divided by 252 Then remainder is 171 = 9999 - 171 The number will be = 9828

[#259] A number exceeds its two fifth by 75. The number is :
Correct Answer

(A) 125

Explanation

Solution: Let the number = x ⇒ According to the question, $$eqalign{
& Rightarrow x - frac{2}{5}x = 75 cr
& Rightarrow frac{{5x - 2x}}{5} = 75 cr
& Rightarrow 3x = 75 imes 5 cr
& Rightarrow x = 125 cr} $$

[#260] The smallest number, which should be added to 756896, so as to obtain a multiple of 11, is :
Correct Answer

(C) 3

Explanation

Solution: For divisibility of 11 = 756896 = (9 + 6 + 7) - (6 + 8 + 5) = 3 So, 3 should be added to number to make it divisible by 11