RBI Grade B 4 Sep 2016

Multiples of 2.3 are alternatively added and subtracted.

18.3 $$+ (2.3 \times 1)$$ = 20.6

20.6 $$- (2.3 \times 2)$$ = 16

16 $$+ (2.3 \times 3)$$ = 22.9

22.9 $$- (2.3 \times 4)$$ = 13.7

13.7 $$+ (2.3 \times 5)$$ = 25.2 $$\neq 2.2$$

25.2 $$- (2.3 \times 6)$$ = 11.4

The pattern followed is :

2 $$\times 1 + 2$$ = 4

4 $$\times 2 + 3$$ = 11

11 $$\times 3 + 4$$ = 37

37 $$\times 4 + 5$$ = 153 $$\neq 151$$

153 $$\times 5 + 6$$ = 771

771 $$\times 6 + 7$$ = 4633

Successive powers of 2 are subtracted.

188 $$- 2^5$$ = 156 $$\neq 154$$

156 $$- 2^4$$ = 140

140 $$- 2^3$$ = 132

132 $$- 2^2$$ = 128

128 $$- 2^1$$ = 126

126 $$- 2^0$$ = 125

The pattern followed is :

6 $$\times 1 - 2$$ = 4

4 $$\times 2 - 3$$ = 5

5 $$\times 3 - 4$$ = 11

11 $$\times 4 - 5$$ = 39

39 $$\times 5 - 6$$ = 189 $$\neq 179$$

189 $$\times 6 - 7$$ = 1127

The series follows the following pattern:

9 * 0.5 + 0.5 = 5

5*1 + 1 = 6

6 * 1.5 + 1.5 = 10.5

10.5 * 2 + 2 = 23

23 * 2.5 + 2.5 = 60

60 * 3 + 3 = 183

Hence, 61 is the incorrect number.

Let additional amount invested by B = $$Rs. 3x$$

=> Additional amount invested by C = $$Rs. 5x$$

Ratio of profits of A, B and C

= $$[1600 \times 12]$$ : $$[2100 \times 8 + (2100 + 3x) \times 4]$$ : $$[1500 \times 8 + (1500 + 5x) \times 4]$$

= $$(4800) : (4200 + 2100 + 3x) : (3000 + 1500 + 5x)$$

= $$(4800) : (6300 + 3x) : (4500 + 5x)$$

=> Total profit = $$(4800) + (6300 + 3x) + (4500 + 5x)$$

= $$15600 + 8x$$

Acc to ques, ratio of total profit to C's share in the profit

=> $$\frac{15600 + 8x}{4500 + 5x} = \frac{3}{1}$$

=> $$15600 + 8x = 13500 + 15x$$

=> $$15x - 8x = 15600 - 13500$$

=> $$x = \frac{2100}{7} = 300$$

$$\therefore$$ Additional amount invested by B = $$3 \times 300$$

= $$Rs. 900$$

Total revenue generated by selling variety A rice = 1.1*15x = 16.50x
Total revenue generated by selling variety B rice = 1.2*10(x+5) = 12x + 60

It is given that, 16.5x - 12x - 60 = 30
$$\Rightarrow$$ x = 20.

When the two varieties been mixed and sold at an overall profit of 20%. Total weight of the entire mixture = 10+15 = 25 kg.
Total cost price of the mixture = 15*20 + 10*25 = 550
Therefore, the cost price pf the mixture per kg = \dfrac{550}{25} = Rs. 22 per kg.
It is known that the mixture was sold at 20%. Therefore, the selling price of the mixture = 1.2*22 = Rs. 26.40.
Hence, option A is the correct answer.

Average of a and b is less than the average of b and c by 1

=> $$\frac{b + c}{2} - \frac{a + b}{2} = 1$$

=> $$(b + c) - (a + b) = 2$$

=> $$c - a = 2$$

$$\because$$ Difference between c and a is positive.

=> $$c > a$$

$$\therefore$$ Quantity I > Quantity II