Test: Average- 4 - CLAT MCQ

Answer – B)34 Explanation : Avg of H  and W age 4yr ago = 30 Present avg age of H  and W = 30+4 = 34

 Option ..( c)  

The average weight of 20 students is 60 kg

Therfore, the total weight of 20 students = 20*60  = 1200 kg 

When the teacher is added then average is increased by  2 kg 

=>  Average weight  of 20 students and 1 teacher become  62 kg. 

=>  Total weight of 20 students and 1 teacher :-

21 * 62 = 1302 kg 

The required weight of teacher:-

=>  [ 1302  - 1200] kg  =  102 kg

So., the right answer is 102 kg. 

Answer – D)38 Explanation : x/2 = 35; x = 70 x/3 = 40; x = 120 5 sub avg = (70+120)/5 = 38

Answer – D)76 Explanation : {(15*75)-(35+46)+(38+63)} / 15 = (1125 – 81 + 101) / 15
= 1145/15 = 76.33 = 76

Answer – C)35.89 Explanation : Let third num = x, 1 numb = 3x, second no = 3x/2 [3x+(3x/2)+x] / 3 = 65.8 11x/2 = 197.4 X = (2×197.4) / 11 = 35.89

Answer – A)75 Explanation : P+Q+R = 84*3 = 252
P+Q+R+S = 4*80 = 320
S = 320 – 252 = 68
Q+R+S+T = 79*4 = 316
Q+R+2S+3 = 316
S =68, Q+R =177
P = 252 – 177 = 75

Answer – B)56 Explanation : X+x+1+x+2+x+3+x+4 = 58*5 = 290 5x+10 = 290 X = 290 – 10/5 = 280/5 = 56

Answer – D)74 Explanation :50+(8*3) = 50 + 24 = 74.

Answer – B)52.5 Explanation : 15 army men age = 15*60 =900 5 army men age = 5*30 = 150 New avg = 900+150/20 =52.5

Answer – D) 108 Explanation : X+X+2+X+4+X+6 = 54*4 = 216
4X+12 = 216
X = 216-12/4 =51
X+6 = 51+6 = 57
Required = 51+57 = 108

Answer – B (2 years) Explanation – Total age of 5 members, 3 years ago = (17 x 5) years = 85 years Total age of 5 members now = (85 + 3 x 5) years = 100 years Total age of 6 members now = (17 x 6) years = 102 years Age of the baby = (102 – 100) years = 2 years

Answer – A (45) Explanation – Let the fourth number be a then hen, third number = 5a, second number= 5a/3 and first=10a/3 a+ 5a+ 5a/3 + 10/3 = 24.75 x 4 so,a=9 So, the numbers are 9, 45, 15 and 30

Answer – B (2 : 3) Explanation – Let the ratio be k:1 Then, k x 16.4 + 1 x 15.4 = (k + 1) x 15.8 (16.4 – 15.8) k = (15.8 – 15.4) k=2/3

Answer – A (Rs 10 and Rs 16) Explanation – Total price of the two books = Rs. [(12 x 10) – (11.75 x 8)] = Rs. (120 – 94) = Rs. 26 Let the price of one book be Rs.x Then, the price of other book = Rs. (x + 60% of x )= x + (3/5)x= (8/5)x so, x +(8/5)x=26 , x=10 The prices of the two books are Rs. 10 and Rs. 16

Answer – C (45) Explanation – Total ages of 30 boys = 14 x 30 = 420 years Total age when class teacher is included = 15 x 31 = 465 years Age of class teacher = 465 – 420 = 45 years

Answer – B (100) Explanation – Let the number of passed candidates be a Then total marks =>120 x 35 = 39 a + (120 – a) x 15 4200 = 39 a + 1800 – 15 a a = 100

Answer – B (56) Explanation – The total of 11 results = 11 x 50 = 550 The total of first 6 results = 6 x 49 = 294 The total of last 6 results = 6 x 52 = 312 The sixth result is common to both: Sixth result = 294 + 312 – 550 = 56

Answer – B (18) Explanation – Total age of all members = 6 x 22 = 132 years 7 years ago, total sum of ages = 132 – (6 x 7) = 90 years But at that time there were 5 members in the family Average at that time = 90 /5 = 18 years

Answer – B (37) Explanation – Let the average after 16th innings be a, then total score after 17th innings => 16a+85 = 17 (a+3) a = 85-51 = 34 Average after 17 innings = a + 3 = 34 + 3 = 37

Answer – B (420) Explanation – Suppose the average expenditure was Rs a.
Then total expenditure = 35a When 7 more students join the mess, total expenditure = 35a + 42 Now, the average expenditure= (35a+42) / (35 + 7) Now, we have (35a + 42)/ 42 =(a – 1) or, 35a + 42 = 42a – 42 7a = 84 a = 12