1. If A, B, C and D are four numbers such that A:B=2:3, B:C=4:5,C:D=5:8, then A:D is equal to-
A. 1:3
B. 3:1
C. 2:3
D. 3:2
(A/D= A/B × B/C ×C/D= 2×4×5/3×5×8 = 1/3 ans)
2. Anita bought some pencils, erasers and papers from a stationary shop. If the ratio of the pencils and the erasers is the same as that of erasers and graph papers and she bought 10 pencils and 40 papers . Find the number of eraser bought by her?
A. 10
B. 20
C. 45
D. 55
(Let no. of eraser be x, then
10:x = x:40……10/x=x/40
X^2 = 40 × 10= 400
X = 20 ans)
3. Two positive numbers x and y are inversely proportional. If x increases by 10% , then y decreases by-
A. 20%
B. 5/11%
C. 100/11%
D. 7/8%
(Required decrease = (a/a+100) × 100%
(10/10+100) × 100 = 100/11% ans )
4. Which of the fractions is the least?
A. 99/100
B. 24/25
C. 68/69
D. 10/11
(since the difference between the numerator and denominator is 1 . Therefore, least the numerator in all the rational numbers is least fraction )
5. A large basket of vegetables contain 3 lemon, 2 tomatoes and 5 capsicums. If a piece of vegetable is chosen at random , what is the probability of getting lemon or a capsicums?
A. 8/7
B. 7/10
C. 4/5
D. 4/7
(Total vegetables= 3+2+5= 10
P(getting lemon or capsicums)= 3/10+ 5/10 = 8/10 i.e 4/5 ans)
6. In how many years will a sum of money becomes double at 5% per annum SI?
A. 12 yr
B. 15 yr
C. 24 yr
D. 20 yr.
(Let P= x , A= 2x
S.I = A-P…. 2x- x = x
S.I= x
Also, S.I= PRT/100
X= x*5*T/100……. T=20 yrs )
7. A farmer sells his two cows. On one, he gains 25% and on the other, he loses 25% .Find his gain or loss % in the whole transaction?
A. 6.25% profit
B. 6.25% loss
C. neither profit nor loss
D. none of these
( In such cases, always loss is incurred.
a^2/100% = (25)^2/100
625/100= 6.25% loss)
8. A chair is bought for Rs. 3000 and sold at loss of 6%. Find its selling price.
A. 2846 Rs
B. 2375 Rs
C. 2795 Rs
D. 2820 Rs
(S.P= 100-L% x C.P
94/100 x 3000 = 2820 Rs)
9. Sum of 9 numbers is 243. Find the average of these 9 numbers.
A. 26
B. 27
C. 28
D. 30
(Average= sum of 9 no.s/9
243/9= 27)
10. The average age of 25 boys in a class decreases by 6 months when a new boy takes the place of a 20 yr old boy . Find the age of a new boy.
A. 7 yr
B. 7.5 yr
C. 8 yr
D. 9 yr
(25×1/2=12.5
New boy age = 20 – 12.5= 7.5 yr )
