(1) 21 years (2) 24 years (3) 30years (4) 40 years Solution: Let Maya’s present age be 6x years and Chhaya’s present age be 5x years. After 15 years, 6x+15/5x+15 = 9/8 ⇒ 48x + 120 = 45x + 135 ⇒ 48x – 45x = 135 – 120 ⇒ 3x= 15 ⇒ x=5 :. Maya’s present age = […]
(1) 8km (2)7km (3) 6 km (4)9km Solution: If the required distance be x km,then x/3-x/4=1/2 ⇒ 4x-3x/12=1/2 ⇒ x/12=1/2 ⇒ x= 6km Then the option is (3) 6km
(1) 25/4 (2) 4 (3)9 (4) 16 Solution: 5√x+12√x=13√x We know that 52+122=132 [PythagoreanTriplet) :. √x =2 ⇒ x = 22 =4 Then the option is (2) 4
If 5√x+12√x=13√x, then x is equal to : Read More »
(1) 50 (2) 40 (3) 42 (4) 32 Solution: The pattern of the given number series is : 5 + 12 = 6 6 + 32 = 15 15 +52= 40 40+72= 89 89+92= 170 Then the missing number is 40.
The missing number in the sequence 5,6,15,…?…. 89,170,291 is: Read More »
(1)4hours (2)4 hours 21.6 sec. (3)5 hours 21.6 sec. (4) None of these Solution: The goods train leaves Delhi at 6 am and mail train at 12 noon, hence after 6 hours The distance covered by the goods train in 6 hours at 32 km per hr. = 32*6= 192 kms The relative velocity of
(1) 807 (2) 907 (3) 970 (4)870 Solution: Rationallsing the denominators. we have x=√3-√2/√3+√2*√3-√2/√3-√2 =(√3-√2)2/(√3)2-(√2)2 = 3+2-2√3*√2/3-2 = 5-2√6 and, y=√3+√2/√3-√2*√3+√2/√3+√2 = (√3+√2)2/(√3)2-(√2)2 = 3+2+2√3*√2/3-2 = 5+2√6 :. x+ y = 5-2√6+5+2√6 = 10 and, xy= (5-2√6) (5+2√6) = 52-(2√6)2 =25-24=1 x3+y3 =(x+y)3-3xy (x+ y) = 103– 3 *10 = 1000 – 30 =970 Then the option is
If x = √3-√2/√3+√2 and y = √3+√2/√3-√2 find the value of x3+y3 : Read More »
Solution: Expression = (53*87+159*21+106*25) = 53 (87+3*21+2*25) = 53 (87+63+50) = 53*200 = 10600 Then the option is (3) 10600
(53*87*159*21*106*25) is equal to: (1)16000 (2)1060 (3) 10600 (4) 60100 Read More »
(1) 11 years 2 months (2) 13 years 6 months (3) 12 years 4 months (4) 10 years 4 months Solution: Total age of initial 30 students = 14years 4 months * 30 = 430 years Total ageof 35 students = 13years 9 months * 35 = (455 + 26)years 3 months = 481 years
Solution: 16 years ago, My age = x years My grandfather’s age = 9x years After 8 years from the present, 9x+ 16+8=3(x+8+ 16) ⇒9x+ 24 = 3x+ 24 + 48 ⇒9x+24=3x+72 ⇒9x- 3x= 72 -24 ⇒6x= 48 ⇒x=48/6 = 8 Required ratio 8 years ago, = (x+ 8) : (9x+ 8) = (8 +
(1) 110 (2) 100 (3) 70 (4) 40k Solution: Ages of the persons = 4x and 7x years. :. 7x-4x=30 ⇒3x=30 ⇒ x=10 :. Sum of their ages = 4x+7x = 11x years = 11*10= 110 years Then the option is (1) 110
