What least number should be added to 1056, so that the sum is completely divisible by 23

Answer: Option C

Answer: Option C

Explanation:

Required digit is = $$\begin{aligned} (4)^{102} + (4)^{103} \end{aligned}$$
as $$\begin{aligned} (4)^2 \end{aligned}$$ gives unit digit 6 so $$\begin{aligned} (4)^{102} \end{aligned}$$ unit digit is 6 and $$\begin{aligned} (4)^{103} \end{aligned}$$ unit digit is, unit digit of $$\begin{aligned} 6 \times 4 \end{aligned}$$ = 4, so answer will be unit digit of 6 + 4 = 0

Answer: Option B

Explanation:

$$\begin{aligned} \frac{abc}{bcd} = \frac{385}{1001} => \frac{a}{d} = \frac{5}{13} \end{aligned}$$ So d = 13

Answer: Option B

Explanation:

Trick: when multiplying with $$\begin{aligned} 5^n \end{aligned}$$ then put n zeros to the right of multiplicand and divide the number with $$\begin{aligned} 2^n \end{aligned}$$
So using this we can solve this question in much less
time.
$$\begin{aligned} 1939392 \times 5^4 = \frac {19393920000}{16} = 1212120000 \end{aligned}$$

Answer: Option C

Explanation:

3*6*9 = 162