6. A building has 120 floors. Every floor is 4 m high. If a balloon rises 4 m every second, how
long will it take to rise from the 42nd floor to the 55th floor?
7. In a test paper of class VII containing 30 questions 5 marked are awarded for every correct
answer and (-3) are awarded for every incorrect answer and 0 for no answer.
(a) Shreystha gets 18 correct answers and 12 incorrect answers. Find her score.
(b) Naman scored 70 marks though he attempted 22 questions. Then find, how many
questions had he attempted incorrectly?
3. Tiya bought a box of chocolates at a cost of 525. The box contains 35 chocolates. What is the
cost of each chocolate?
Kundan went to play with 50 marbles. In 7 games he gained 4 marbles each and in 3 games he
gained 6 marbles each. How many marbles did kundan have after ending of the game ?
· The daytime maximum temperature in Kolkata on a particular day was 35º C. At night the
temperature became 26° C. What is the rise in temperature from daytime to night-time?
Answers
Answered by
0
Q7. 5 Questions
Step by Step explanation
Let the questions scored correctly by Naman be x.
The questions scored wrongly will be = 22 - x
We rewrite this as follows :
5x + [-3 (22 - x)] = 5x - 66 + 3x
5x + 3x - 66 = 70
8x = 70 + 66
8x = 136
x = 136/8
x = 17
The questions he got correct were 17 questions.
The questions he got wrong were :
22 - 17 = 5
He got 5 questions wrong.
The answer is therefore 5.
Similar questions