NCERT 2022 | मानव नेत्र तथा रंगबिरंगा संसार - L8 | Human eye and colorful world | Ruchi Ma'am| 10 AM

Class 10 Science | Chapter 11 Human Eye and The Colorful World | Important Questions and Quick Revision |

Ashok left from place A for place B at 8 a.m. and Rahul left place B for place A at 10.00 a.m. the dis-tance between place A and B is 637 km. If Ashok and Rahul are travelling at a uniform speed of 39kmph. and 47 kmph respectively, at what time wilt they meet? 5: 30 b. 4: 30 c. 5 p m d. 4 p m

Pipes A and B can fill a tank in 16 hours and 24 hours, respectively, and pipe C alone can empty the full tank in x hours. All the pipes were opened together at 10.30 a.m., but C was closed at 2:30 p.m. If the tank was full at 8:30 p.m. on the same day, then what is the value of x ? पाइप A और B किसी टंकी को क्रमशः 16 और 24 घंटे में भर सकते हैं , तथा पाइप C अकेला भरी हुई टंकी को x घने में खाली कर सकता है | सभी पाइपों को सुबह 10 : 30 बजे एक साथ चालू किया गया, लेकिन 2 : 30 pm में C को बंद कर दिया गया | यदि टंकी उसी दिन 8 :30 pm में भर गई, तो x का मान ज्ञात करें |

Factorise the expressions. (i) ax^2 + bx (ii) 7p^2 + 21q^2 (iii) 2x^3 + 2xy^2 + 2xz^2 (iv) am^2 + bm^2 + bn^2 + an^2 (v) (lm + l) + m +1 (vi) y(y+z) + 9(y+z) (vii) 5y^2 - 20y - 8z + 2yz (viii) 10ab + 4a + 5b +2 (ix) 6xy - 4y + 6 - 9x