The total marks obtained by Ramesh in Hindi, English and Mathematics together is 90 more than the marks obtained by him in English. What are the average marks obtained by him in Hindi and Mathematics together?
The cost (per Kg) of 3 qualities of rice are 45, 42 and 35 respectively. The cost (per Kg) of a mixture of 10 Kg of first, 8 Kg of second and 7 Kg of third will be
The sum of a number of two digits and the number obtained by exchanging the places of digits is 110. If units place is 4 more than the tens place in the given number, then product of two digits of the number will be
let no be yx
given x-y=4...(1)
xy+yx=110 equivalent to x+y+10(x+y)=110
i.e. x+y=10...(2)
solving (1)&(2) we get x=7,y=3
i.e. the no. is 37
product will be 3*7=21
A train 130 m long passes a bridge in 21 seconds moving at a speed of 90 Km/h. Find out the length of the bridge
OPtion
1. 395 m.
2. 420 m.
3. 425 m.
4. 380 m.
5. 386 m.
6. 352 m.
7. 365 m.
8. 368 m.
9. 399 m.
10. None of the above
Solution
We have, speed of the train
= (length of the train + length of the bridge) / time taken in crossing the bridge
⇒ 5/18 x 90 = (130 + length of the bridge)/ 21
= 450 x 21 = 2340 + 18 (length of the bridge)
= 9450 – 2340 = 18 (length of the bridge)
∴ Length of the bridge
= 7110 / 18 = 395 m.
The average weight of 31 students of section A of a class is 53 Kg, whereas the average weight of 27 students of section B of the same class is 55 Kg. Find out average weight of all the 58 students of the class
OPtion
1. 59.3 kg
2. 55.5 kg
3. 52.6 kg
4. 53.9 kg
5. 55.6 kg
6. 58.2 kg
7. 54.2 kg
8. 53.1 kg
9. 60.2 kg
10. None of the above
Solution
Here, n1 = 31, n2 = 27, x = 53, and y = 55.
∴ Average weight of all the 58 students = (n1x + n2y)/(n1+n2)
= [(31x53) +(27x55)]/ (31+27)
= (1643 +1485)/58
= 53.9kg