1. What least number should be added to 1056, so that the sum is completely divisible by 23
4
1
2
3
Answer: Option C
Explanation:
(1056 / 23) gives remainder 21
21 + 2 = 23, So we need to add 2
2. 587 * 999 = ?
586411
586413
486411
486413
Answer: Option B
Explanation:
Trick: 587 * (1000 - 1) = 587000 - 587 = 586413
3. A number when divided by 44, gives 432 as quotient and 0 as remainder. What will be the remainder when dividing the same number by 31
5
3
4
6
Answer: Option A
Explanation:
P ÷ 44 = 432
=> P = 432 * 44 = 19008
P / 31 = 19008 / 31 = 613, remainder = 5
4. How many terms are there in 2,4,8,16,....,1024
7
8
9
10
Answer: Option D
Explanation:
It is a GP. with r = 2, ie \begin{aligned} 2^1, 2^2, 2^3... \end{aligned}
If number of terms is n. Then,
\begin{aligned} 2 \times 2^{n-1} = 1024 \end{aligned} =>
\begin{aligned} 2^{n-1} = 512 \end{aligned}
or \begin{aligned} 2 \times 2^{n-1} = 2^9 \end{aligned}
so n-1 = 9 => n = 10