1. The seven digit number 43567X is divisible by 3, where X is a single digit whole number. Find X.
A. 2
B. 5
C. 8
D. All of these
Answer: Option D
Explanation:
A number is divisible by 3 when sum of its digits is divisible by 3.
Here, sum of digits = 4 + 3 + 5 + 6 + 7 + X = 25 + X. So, X can be 2, 5, 8 which gives the sum 27, 30 and 33 respectively.
Therefore, X has 3 values here, for which the number is divisible by 3. So, the answer is option D.
2. Simplify the expression using BODMAS rule ([latex]\frac{3}{7}[/latex]) of ([latex]\frac{4}{5}[/latex]) of 20 ([latex]{25}^{2}[/latex] - [latex]{24}^{2}[/latex])
A. 336
B. 168
C. 84
D. None of these
Answer: Option A
Explanation:
([latex]\frac{3}{7}[/latex]) × ([latex]\frac{4}{5}[/latex]) of 20 (625 - 576)⇒ ([latex]\frac{3}{7}[/latex]) × ([latex]\frac{4}{5}[/latex]) × 20 × 49 =336
3. Simplify the expression using BODMAS rule (105 + 206) - 550 ÷ [latex]{5}^{2}[/latex] + 10
A. 399
B. 289
C. 298
D. 299
Answer: Option D
Explanation:
(105 + 206) - 550 ÷ 52 + 10
= 311 – 550 ÷ 25 + 10
= 311 – 22 + 10
= 289 + 10 = 299
4. Simplify the expression using BODMAS rule:: ([latex]\frac{3}{3}[/latex]) of ([latex]\frac{4}{7}[/latex]) {(10 × 3) – (8 × 2)}
Answer: Option B
Explanation:
Applying BODMAS rule = ([latex]\frac{3}{2}[/latex]) of ([latex]\frac{4}{7}[/latex]) {30 – 16} = ([latex]\frac{12}{14}[/latex]) × 14 = 12
5. The six-digit number 54321A is divisible by 9 where A is a single digit whole number. Find A.
Answer: Option D
Explanation:
A number is divisible by 3 when sum of its digits is divisible by 3.
Here, sum of digits = 4 + 3 + 5 + 6 + 7 + X = 25 + X. So, X can be 2, 5, 8 which gives the sum 27, 30 and 33 respectively.
Therefore, X has 3 values here, for which the number is divisible by 3.