Three girls start jogging from the same point around a circular track and they complete one round in 24 seconds,

Time taken = 2 min 20 sec = 140 sec.  Radius, r = 100 m.  In 40 sec the athlete complete one round.  So, in 140 sec the athlete will complete = 140...

Solution: 9 = 3 x 3 = 32 12 = 2 x 2 x 3 = 22 x 3 15 = 3 x 5 => LCM (9, 12, 15) = 22 x 32 x 5 = 180 => the bells will toll together...

Let the no. of girls be 5x No. of boys=7x According to the question 5x+8=7x 7x-5x=8 2x=8 x=8/2 x=4 No. of girls=5*4=20 no. of boys=7*4 or 5*4+8=28 Hence the total strength of the class is 20+28=48

Let us denote 2 boys and 2 girls in room X as B1, B2 and G1, G2 respectively. Let us denote 1 boy and 3 girls in room Y as...

False, because the outcomes are not actually, likely. For no girl, the outcome is bbb, for one girl, it is bgb, gbb, bbg, for two girls, it is bgg, ggb, gbg and...

(b) Required time = L.C.M of 24, 36 and 30 = 360 seconds = 6 minutes

(c) They will be together at the starting point after the L.C.M of 36, 48 and 42 L.C.M. of 36, 48, 42 = 1008 seconds

Leaving one seat vacant between two boys may be seated in 4! ways. Then at remaining 5 seats, 5 girls any sit in 5! ways. Hence the required number =...

(d) Assume the 2 given students to be together (i.e one]. Now there are five students. Possible ways of arranging them are = 5! = 120 Now, they (two girls) can arrange themselves...

(a) Here, A and B are moving in opposite directions. So, Relative speed = 2 + 3 = 5 rounds/hour So, they cross each other 5 times in an hour...