Official Quant thread for CAT 2013

19rsb · November 18, 2012, 5:08pm

@sujamait said:
31 is following...bhai log sab kaha gayab rahte ho...jaise hee Q post karo..sab toot padte hein..but Q koi post nhn karta hai sahi hai..A jewelry box, made of thin sheet of Brass, consists of two parts €“ a cubical box, in which a banglewith outer circumference of 22 cm just fits in and a hollow cover in form of a right pyramid thatcompletely fits over the top of the cubical box. If the slant height of a face of the cover is 12.5 cm,find the volume of the box.A. 350 cm3 B. 392 cm3 C. 529 cm3 D. 539 cm3

529???

sarayusheshadri · November 18, 2012, 5:08pm

@sujamait said:
31 is following...bhai log sab kaha gayab rahte ho...jaise hee Q post karo..sab toot padte hein..but Q koi post nhn karta hai sahi hai..A jewelry box, made of thin sheet of Brass, consists of two parts €“ a cubical box, in which a banglewith outer circumference of 22 cm just fits in and a hollow cover in form of a right pyramid thatcompletely fits over the top of the cubical box. If the slant height of a face of the cover is 12.5 cm,find the volume of the box.A. 350 cm3 B. 392 cm3 C. 529 cm3 D. 539 cm3

539..

2pi*r = 22

r= 7/2

cube side = 7

height of pyramid = 12.5^2 - 3.5^2 = 12

volume = 1/3*7*7*12 = 196

so total 343+196 = 539

ashmukh · November 18, 2012, 5:10pm

@sujamait said:
31 is following...bhai log sab kaha gayab rahte ho...jaise hee Q post karo..sab toot padte hein..but Q koi post nhn karta hai sahi hai..A jewelry box, made of thin sheet of Brass, consists of two parts €“ a cubical box, in which a banglewith outer circumference of 22 cm just fits in and a hollow cover in form of a right pyramid thatcompletely fits over the top of the cubical box. If the slant height of a face of the cover is 12.5 cm,find the volume of the box.A. 350 cm3 B. 392 cm3 C. 529 cm3 D. 539 cm3

529??

shadowwarrior · November 18, 2012, 5:11pm

@sujamait said:
Bhanu and Ria start running simultaneously on a linear track with same speeds and cover first280 m in €˜t €™ seconds. After covering every 280 m, Bhanu decreases her speed by fraction of1/2andRia decreases her speed by fraction of2/3Bhanu takes 1.5t minutes less than the time taken byRia to cover the entire distance. Find the distance, which in metres is an integer multiple of 280?A. 2800 B. 1680 C. 1400 D. 2240

1400 mt....?

ashmukh · November 18, 2012, 5:12pm

@Ashmukh said:
539

sujamait · November 18, 2012, 5:14pm

@kumargaurav_bn said:
99) a, b, c and d are real positive numbers such that a + b = 5, c + d =2 and ad = bc = 1. Then ac + bd + aca) 11.5 b) 12.5 c) 10.5 d) 13 e) none of thes

18 ke aspass

sujamait · November 18, 2012, 5:16pm

@scrabbler said:
539.Cube of side 7 = vol of 343Pyramid of base 7 x 7 and height 12 = vol 1/3 x 7 x 7 x 12 = 196.Total volume 343 + 196 = 539.Technically though volume of box alone should be 343 regardsscrabbler

got the same.

Two persons are travelling in the same direction but on either side a tower. They noticed that the
angle of depression made by a man at the top of the tower is 30° and 60°. After
6 minutes, the two persons noticed that the angle of depression made by the man at the top of the
tower is 45° for each of them. If the height of the tower is 6 metres, find the distance (in metres) that
the slower person will travel in 15 minutes, travelling with the same speed?
A. 30( rt3 − 2) B. 5( rt3 −1) C. 5 3 (rt 3 −1) D. None of these

kumargaurav_bn · November 18, 2012, 5:17pm

@sujamait bhai a upon c hai

shadowwarrior · November 18, 2012, 5:19pm

@kumargaurav_bn said:
99) a, b, c and d are real positive numbers such that a + b = 5, c + d =2 and ad = bc = 1. Then ac + bd + aca) 11.5 b) 12.5 c) 10.5 d) 13 e) none of thes

10.5....?

i think the expr for which we need to find the value of is:
"ac + bd + {a/c}" and not "(ac+bd+a)/c"(as i thought initially)

sarayusheshadri · November 18, 2012, 5:19pm

@sujamait said:
Bhanu and Ria start running simultaneously on a linear track with same speeds and cover first280 m in €˜t €™ seconds. After covering every 280 m, Bhanu decreases her speed by fraction of1/2andRia decreases her speed by fraction of2/3Bhanu takes 1.5t minutes less than the time taken byRia to cover the entire distance. Find the distance, which in metres is an integer multiple of 280?A. 2800 B. 1680 C. 1400 D. 2240

1.5 t mins?

I don't think that can happen..

soham2208 · November 18, 2012, 5:20pm

@kumargaurav_bn said:
99) a, b, c and d are real positive numbers such that a + b = 5, c + d =2 and ad = bc = 1. Then ac + bd + aca) 11.5 b) 12.5 c) 10.5 d) 13 e) none of thes

After some random manipulation, I pinned the question as (ac+ bd) + (a/c)

and NOT (ac +bd+a)/(c) :|

Anyways, (a + b)*(c+d) = 10 => ab + ad + bc + bd = 10 => ac + bd = 8

Now, ac + bd + (a/c) = 8 + (a/c) = 8 + (1/cd)

a = 1/d, b = 1/c

=> 1/c + 1/d = 5 => cd = 2/5

=> Ans = 8 + 5/2 = 10.5 ?

kumargaurav_bn · November 18, 2012, 5:23pm

Find the number of solutions in real numbers x^4 + |x| = 10
a) 0 b) 1 c) 2 d) 4 e)8

shadowwarrior · November 18, 2012, 5:25pm

@sujamait said:
got the same.Two persons are travelling in the same direction but on either side a tower. They noticed that theangle of depression made by a man at the top of the tower is 30° and 60°. After6 minutes, the two persons noticed that the angle of depression made by the man at the top of thetower is 45° for each of them. If the height of the tower is 6 metres, find the distance (in metres) thatthe slower person will travel in 15 minutes, travelling with the same speed?A. 30( rt3 − 2) B. 5( rt3 −1) C. 5 3 (rt 3 −1) D. None of these

5rt(3) * {rt(3) - 1}....?

vijay_chandola · November 18, 2012, 5:25pm

Let O, A, B, C be four points in a plane such that OA = OB = 15 and OC = 7. What is the maximum area of the triangle ABC?

deedeedudu · November 18, 2012, 5:27pm

@sujamait said:
Bhanu and Ria start running simultaneously on a linear track with same speeds and cover first280 m in €˜t €™ seconds. After covering every 280 m, Bhanu decreases her speed by fraction of1/2andRia decreases her speed by fraction of2/3Bhanu takes 1.5t minutes less than the time taken byRia to cover the entire distance. Find the distance, which in metres is an integer multiple of 280?A. 2800 B. 1680 C. 1400 D. 2240

1400

shadowwarrior · November 18, 2012, 5:27pm

@kumargaurav_bn said:
Find the number of solutions in real numbers x^4 + |x| = 10a) 0 b) 1 c) 2 d) 4 e)8

c)2 solns....?

sarayusheshadri · November 18, 2012, 5:29pm

@vijay_chandola said:
Let O, A, B, C be four points in a plane such that OA = OB = 15 and OC = 7. What is the maximum area of the triangle ABC?

105 sq units?

krum · November 18, 2012, 5:30pm

@vijay_chandola said:
Let O, A, B, C be four points in a plane such that OA = OB = 15 and OC = 7. What is the maximum area of the triangle ABC?

1/2*30*7=105

19rsb · November 18, 2012, 5:31pm

@sujamait said:
got the same.Two persons are travelling in the same direction but on either side a tower. They noticed that theangle of depression made by a man at the top of the tower is 30° and 60°. After6 minutes, the two persons noticed that the angle of depression made by the man at the top of thetower is 45° for each of them. If the height of the tower is 6 metres, find the distance (in metres) thatthe slower person will travel in 15 minutes, travelling with the same speed?A. 30( rt3 − 2) B. 5( rt3 −1) C. 5 3 (rt 3 −1) D. None of these

D?????=>5(3-rt3)

deedeedudu · November 18, 2012, 5:33pm

@sujamait said:
got the same.Two persons are travelling in the same direction but on either side a tower. They noticed that theangle of depression made by a man at the top of the tower is 30° and 60°. After6 minutes, the two persons noticed that the angle of depression made by the man at the top of thetower is 45° for each of them. If the height of the tower is 6 metres, find the distance (in metres) thatthe slower person will travel in 15 minutes, travelling with the same speed?A. 30( rt3 − 2) B. 5( rt3 −1) C. 5 3 (rt 3 −1) D. None of these

5(3-root(3))
I guess its NOT