Rationale: 3-letter codes = 26^3;
4-letter codes = 26^4;
5-letter codes = 26^5;
Total = 26^3 + 26^4 + 26^5 = 26^3(1+26) + 26^5 = 26^3*27 + 26^5.
The answer: (D)
Question: All of the bonds on a certain exchange are designated by a 3-letter, a 4-letter, or a 5-letter code that is created by using the 26 letters of the alphabet. Which of the following gives the maximum number of different bonds that can be designate with these codes?
Options:
(A) 26(26^3 + 26^4)
(B) 26(26^3 + 26^5)
(C) 27(26^3 + 26^5)
(D) 27(26^3) + 26^5
(E) 26^3 + 27(26^5)
Reasoning: S = (110 + 280 /38 = 390/38 * 18/5 = 40
Ans: (C)
Question: A train 110 meters long completely crosses a 280 meters long bridge in 38 seconds. What is the speed of the train is?
Options:
(A) 32
(B) 45
(C) 40
(D) 66
(E) 09
Rationale: Amount of gas you added to your car: 19-x
Price per gallon: (19-x)/20
The answer: (C)
Question: You are filling up your car with gas. Your tank can hold 19 gallons. Your car started with x gallons in it. You paid $20 in gas. What was the cost of gas per gallon?
Options:
(A) 19/20
(B) x/20
(C) (19-x) /20
(D) x-19) /20
(E) 19+20/x
Reasoning: Distance covered by the car = 80 9 = 720 km
\ Speed = 7206 = 120 km/hr
\ Speed gain = 120 80 = 40 km/hr
Ans: (B)
Question: A car finishes a journey in nine hours at the speed of 80 km/hr. If the same distance is to be covered in six hours how much more speed does the car have to gain?
Options:
(A) 8 km/hr
(B) 40 km/hr
(C) 12 km/hr
(D) 16 km/hr
(E) None of these
Rationale: Money paid in cash = Rs. 1000
Balance payment = (10000 - 1000) = Rs. 9000
The answer: (A)
Question: The price of a T.V. set worth Rs. 10000 is to be paid in 20 installments of Rs. 1000 each. If the rate of interest be 6% per annum, and the first installment be paid at the time of purchase, then the value of the last installment covering the interest as well will be?
Options:
(A) 9000
(B) 26699
(C) 96000
(D) 19000
(E) 26711
Rationale: (Place value of 6) - (Face value of 6) = (6000 - 6) = 5994
The answer: (A)
Question: The difference between the place value and the face value of 6 in the numeral 856973 is
Options:
(A) 5994
(B) 6973
(C) 973
(D) 1000
(E) 7000